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Full text of "Maftex: the thermal-insulating board that has structural strength."

1 












Mjvftex 

77^^ ''^hermal-Insulattryf'BoQtd 
that has Structural Stjvn^th 



A PRACTICAL and complete 

reference guide for those 

interested in the effectiveness, 

economy and appHcation of 

insulating material. 



Compiled in collaboration with the 
Structural Service Bureau — D. Knickerbacker Boyd, F.A.I.A., Consulting Architect 

MacAndrews & Forbes Company p 

200 FIFTH AVENUE, NEW YORK 21 



CO c 

3 
o* 



1^ 




Licorice root being transported 

to one of the baling stations 

of MacAndrews & Forbes Company 

through the famous ruins of Ephesus. 



INTRODUCTION 

MAFTEX— The ^Thermal Insulating" Board that has Struc- 
tural Strength— offers the Architect, builder and owner some 
very definite advantages in structural strength, insulating 
efficiency and economy. 

Some of these outstanding advantages are that MAFTEX 

—is composed of licorice root; a tough, fibrous undersoil growth that 

requires 4 to 5 years to mature. 
— is a homogeneous mass of single-ply construction. 
• — has a thermal conductivity rating of 0.34. 
— has a resistance to distortion much greater than wood when used 

as sheathing. 
— has great nail holding power, 
—has a bonding strength with plaster of over 1,000 pounds per square 

foot. 
— replaces wood sheathing and lathing with less cutting and less 

waste. 
— saves from 20 to 30% on fuel bills depending upon the type of 

construction. 



1 




Peiham-Biltmore Apartment, Pelham, N. Y.— MAFTEX structural insulating 
board used as plaster base and sound deadener on all main partition walls. 
MAFTEX Roof Insulating Board used on entire roof area for roof insulation. 

[2] 




Safinas (picturesque sailing boats) on the Tigris River loaded witli licorice root, 

bound for the MacAndrews & Forbes Company's baling station at 

Basrah, Mesopotamia. 



CONTENTS 



.Page 3 



.Page 11 



Chapter I 

Raw Material 
Manufacture 
Properties of MAFTEX 
Tests of MAFTEX 

Chapter II 

General Applications 
Roof Sheathing 
Side Wall Sheathing 
Plaster Base 
Sound Deadening 
Wall Finish 



Chapter III Page 1 3 

Sheathing on Walls and Sloping Roofs 
Value of Sheathing 
Recommended Practice 
Direaions for Application 

As sloping roof and wall sheathing 

Chapter IV Page 23 

Interior Decoration 

Paneled Walls and Ceilings 
Painting or Staining 

Chapter V Page 29 

Sound Deadening 

Characteristics of Sound 



Methods of Sound Deadening 

Partinon construction 

Floor construction 
Accoustical Correction 

Chapter VI Page 37 

MAF-LATH Insulating Plaster Base 
Reason for Enduring Bond 
Insulation Value 
Application 

Methods 

Advantages 
Application of Plaster 
MAFTEX as Plaster Base 
General Notes on Plastering 

Chapter VII Page 3L 

MAFTEX Roof Insulanng Board 
As Flat Roof Insulation 
For Elimination of Condensation 
Under Built-up Roofing 

Concrete Roof Decks 

Wood Roof Decks 

Unit Tile Decks 

Metal Roof Decks 

As Base for Linoleum 

Data on Flat Roof Construction 

Use of Roof Condensation Chart 



The ^ ^Thermal-Insulating^^ Board 
that has Structural Strength 



tn 




Stacking freshly dug licorice roots at Sochi a, Turkey. 



CHAPTER I 



THERE are very definite reasons for the unusual 
structural strength, insulating ability and econo- 
mies of MAFTEX. These reasons can be, and 
have been, logically traced from the digging of the 
licorice roots to the service obtained from MAFTEX 
in actual installations. 

Raw Material 

From Spain, Italy, Greece, Turkey, Southern 
Russia, Asia Minor, Afghanistan and China come 
the tough licorice roots which compose MAFTEX 
—The ^Thermal Insulating" Board that has Struc- 
tural Strength. 

Licorice Roots Naturally Tough 

These licorice roots are a slow, undersoil growth 
and are not harvested for four to five years. Their 
mode of growth through stub- 
born soil necessarily makes them 
tougher than the fiber struc- 
tures of growths that mature 
in three or four months. 
Their very life depends upon 
their ability to withstand mois- 
ture without disintegration. 
These inherent qualities of 
toughness and moisture-resist- 
ance found in the licorice root 
are found also in the finished 
product— MAFTEX. 




MAFTEX used for third floor insulation in beauti- 
ful Wilmington (Del.) residence. 
Walter Carlson, Wilmington, Delaware, architea. 

in 



Manufacture 

The licorice roots are shredded and extracted, 
which includes boiling or "cooking" for hours to 
extract all of the useful non-fibrous material and 
to effect complete sterilization. Then they are fur- 
ther refined and cleansed of foreign substances, and 
finally the fibers are thoroughly waterproofed. 

"Dead-Air" Cells Formed 

The long, tough, reinforcing fibers are then 
passed through many presses that felt them into a 
closely compacted board containing millions of 
microscopic "dead-air" cells that check the passage 
of heat and form a continuous single-ply board 
without laminations. The board is then "seasoned" 
by drying at a temperature of 350°, cut into stand- 
ard sizes, inspected, gauged and sent to the ware- 
house to be packed and shipped as MAFTEX — 
The "Thermal -Insula ting" 
Board that has Structural 
Strength. 



Properties of MAFTEX 

MAFTEX Structural Insu- 
lating Board provides effective 
protection against thermal 
losses, due to its millions of 
"dead-air" cells, which are an 
effective barrier to the passage 
of heat. 



MAFTEX always retains all its inherent qualities, 
so that it never buckles, cracks, warps nor disin- 
tegrates after being applied. 

MAFTEX is thoroughly impregnated with a 
waterproofing material which makes it extremely 
resistant to moisture and non-absorbent to water. 

MAFTEX STRUCTURAL INSULATING 
BOARD has the strength and resiliency to withstand 
windstrain, vibration and atmospheric change with- 
out the supplementary use of roof or side wall 
sheathing. 

MAFTEX ROOF INSULATING BOARD is 
thicker than Structural MAFTEX and its insulating 
value is therefore somewhat higher. It is for insulat- 
ing purposes only on flat roofs and similar locations 
where structural strength is not such an important 
factor. 

MAFTEX is easily and quickly handled. It saws 
and nails cleanly, and greatly reduces construction 
time, effort and cost. 

MAF-LATH has all the qualities of Structural 
MAFTEX — but is in more convenient size for use 
by lathers. It provides an excellent base for plaster 
in place of lath and requires no forcing of ground 
coats through to key. 




Complete Apparatus for Thermal Conductivity Test with the 

Guarded Hot-PIate in exact accordance with the code of 

A. S. H. & V. E. 



MAFTEX Tests 

For Thermal Conductivity 

There are two well-known methods for testing 
the thermal conductivity of building materials — the 




Apparatus for the "Hot-Box" Method of testing conductivity. 

"Hot Box" Method and the "Guarded Hot-Plate" 
Method. 

Two Methods Used 

Tests by both methods have been made a great 
many times to determine the insulating value of 
MAFTEX. Most tests at the present time are con- 
ducted by the "Guarded Hot-Plate" method, how- 
ever, as this method is now universally accepted as 
the standard by all authorities. 

Daily Runs Tested 

The daily runs of MAFTEX are tested by the 
latter method in the laboratories of the manufac- 
turer. These tests indicate that a coefficient of 0.34 
B.t.u. per hour, per square foot, per inch thickness, 
per degree Fahrenheit difference in temperature 
may be regarded as a con- 
servative figure for MAF- 
TEX. 



Special Conductivity Tests 

Professor G. F. Gebhardt, 
using the -"Guarded Hot- 
Plate" Method, determined 
the conductivity of MAF- 
TEX to be 0.337 B.t.u. 
Professor William Allen 
Sloan in tests in the Mechan- 
ical Engineering laboratory 
of the University of Penn- 
sylvania by the "Hot Box" 
Method, found MAFTEX to 
have a value of 0.326 B.t.u. 




A twenty year old experi- 
mental board fabricated 
from licorice roots shows 
no trace of disintegration, 
no inherent change, no 
loss of tensile strength. 



[6] 




Apparatus for the "Guarded Hot-Plate" method of 
testing conductivity. 

The accompanying table shows at a glance the 
comparative conductivity of various building ma- 
terials. The conductivity (C) is expressed in terms 
of B.t.u. per hour, per square foot, per inch thick- 
ness, per degree Fahrenheit difference in temperature. 

C 
MAFTEX 0.34 

WOOD (Across Grain) 

Cypress 0.67 

White Pine 0.78 

Mahogany 0.90 

Virginia Pine 0.96 

Oak . . 1.30 

Maple 1.10 

MISCELLANEOUS BUILDING MATERIALS 

Cinder Concrete 2 to 3 

Building Gypsum About 3 

Plaster Board 2 to 8 

Building Brick 3 to 5 

Glass 5 to 6 

Limestone 4 to 16 

Concrete 6 to 9 

Sandstone 8 to 16 

Marble 9 to 24 

Granite . ..13 to 28 




One of the twelve vast ware- 
nouses for storage of licorice root 
at the Camden plant of Mac- 
Andrews & Forbes. 



When it is borne in 
mind that the lower the 
conductivity the better 
the material for insulat- 
ing purposes, it is easy 
to see the advantage of 
MAFTEX with its con- 
servative rating for con- 
ductivity of 0.34. 

For Strength 

In addition to its in- 
sulating qualities, MAF- 
TEX has unusual struc- 



tural strength, as proved by numerous experimental 
tests and by actual service. 

The greatest necessity for this structural value 
is of course in the construction of wood frame build- 
ings, where sheathing acts as an integral part of 
the structural support — stiffening and bracing the 
wood studs, joists and rafters. 

MAFTEX Compared with Wood 

In this connection it is interesting to note the 
comparative strength for sheathing of wood and 
MAFTEX, as indicated by the turnbuckle test shown 
in the illustrations on the next page. 

When subjected to the same loading, the displace- 
ment of the wood panel was more than 5 times as 
much as the displacement of the MAFTEX. When 
the turnbuckle was released, the MAFTEX re- 
covered 54 per cent, whereas the wood sheathing 
recovered 17 per cent. This latter result is of par- 
ticular interest when taken in connection with the 



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A comparison of the MAFTEX coefficient of conductivity of 0.34 

with other materials quickly reveals the insulating 

value of MAFTEX. 



[7] 




Start of Distortion Test on a panel of MAFTEX and a panel of wood sheathing. Each of the 
panels was 8 feet square. The studs were placed 16 inches on centers. One panel was sheathed with 
MAFTEX nailed in accordance with manufacturer's directions. The other panel was covered with 
ordinary 7/8 inch wood sheathing 12 inches wide with each board nailed to each stud with tour 8d 
nails. A turn-buckle at the top provided an absolutely equal pull on each of the panels. 



initial distortion, as it is convincing evidence of 
the extreme elasticity and resistance to strain of 
MAFTEX. 

Diagonal Sheathing Tests 

Similar tests were run on panels of MAFTEX 
and diagonal wood sheathing — with the sheathing 
laid sloping diagonally toward, as well as away 
from, the MAFTEX panel. The results showed 
that the MAFTEX panel has practically the same 
or even a slightly greater strength than diagonal 
sheathing. As pointed out on page 16 diagonal 
sheathing is not good practice and should not be 
used, particularly for stucco. 

Nail Holding 

One of the most interesting tests to determine 
the nail holding power of MAFTEX is shown in 
the illustration. It took a 250 pound pull before 
the four 6-penny nails with y^'^ heads gave way. 
Three nails were pulled from the wood block, while 
the head of only one nail was pulled through the 




NAIL HOLDING TEST 

A ten inch square of MAFTEX was nailed to a slab of seasoned 
wood with four 6-penny nails having y^" heads. The nails 
were spaced four inches apart on centers and the MAFTEX 
bolted to a block base. The load was applied by a chain hoist 
and it was not until the test scales recorded a 250 pound pull 
that the nails gave. Three nails were pulled from the wood while 
the head of only one nail was pulled through the MAFTEX. 
Naturally this was a vastly greater strain than would possibly be 
exerted in normal forms of construction, and is an excellent 
indication of the toughness of MABTEX. 



[8] 




End of Distortion Test. After the turn-buckle huu U.., ^rv.a ci^hty-four turns, the MAFTEX panel was only 2A 

!^ffA''^ptP^""'^ ^^'''f '^' T^^ PfS'* '^'? ^^y^ ^"^^^^^ ^^^^ ^^^ perpendicular. After the load wa removed 
the MAFTEX panel returned more than 54% so that it was only 1^^ inches off. The" wood panel recovered on^ 17% 

so that it was still 10% inches from plumb. ^ 

This extreme resistance to distortion and strain provides convincing evidence of the structural strength of MAFTEX 




PLASTER BOND TEST 

A MAFTEX board was given the usual three-coat plaster surface. 
After the plaster was thoroughly seasoned, samples were cut out 
in four inch squares. These samples were then attached to blocks 
of wood by applying coatings of hot asphalt. Rings were fastened 
to the blocks and after the asphalt had hardened the sample was 
ready for test. A chain hoist with test scales was used to apply the 
load. In repeated tests it has been found that a load of over one 
thousand pounds to the square foot did not affect the bond between 
MAFTEX and plaster— but that It was the MAFTEX itself which 
ruptured. Such tests are a wonderful demonstration of the 
strength of not only the bond but of the MAFTEX boards as well. 



[9] 



MAFTEX. This is of course a much greater strain 
than would possibly be encountered in normal forms 
of construction, and certainly provides excellent 
proof of the toughness of MAFTEX. 

Plaster Bond 

Extensive tests have been made to prove that 
plaster will adhere to, and form a strong, lasting 
bond with MAFTEX. The MAFTEX board was 
given a three-coat plaster surface in accordance with 
usual practice. The surface was thoroughly seasoned. 
In repeated tests (details of which are given under 
the illustration) it has been found that a load of 
over one thousand pounds to the square foot was 
required to cause a rupture. Then it was not 
the bond between MAFTEX and plaster, but the 
MAFTEX itself which ruptured. These tests proved 
not only the tremendous strength of the plaster bond 
but also the unusual strength of the MAFTEX 
board itself. 

Bonding Strength Proved 

As a means of determining the reason for this 
great plaster bonding strength photo-micrographs 
were taken of MAFTEX without plaster, and then 



with plaster removed, so as to expose what had 
been the bonding surface. The results are shown 
in the accompanying illustrations. 

They show how the gypsum plaster penetrated 
into the millions of valleys between the hills and 
into the craters formed by the licorice root fibers— 
and how the millions of tiny fibers on the surface 
of the MAFTEX board bonded with the plaster. 

Resists 1000-Pound Pull 

This penetration of the plaster into the minute 
holes in the surface, plus the fibers which were 
deeply buried in the plaster, account for the tre-, 
mendous bond which even a pull of over a thou- 
sand pounds per square foot could not rupture. 



Summation of MAFTEX Tests 

These various tests to which MAFTEX has been 
subjected show — 

(1) A themial conductivity rating of 0.34 B.t.u. 

(2) One-fifth the amount of distortion of wood 
sheathing under equal load— and a recovery of 
54 per cent as compared with 17 per cent for 
wood sheathing. 

(3) An ability to hold four nails up to 250 pounds 
pull— and then have only one nail head out of 
four pull through the MAFTEX. 

(4) A plaster bond which did not rupture even 
though subjected to a pull of over 1000 pounds 
per square foot. 



1 




Figure 1 




Figure 2 



These Photo-Micrographs show the enduring bonding abiHty of Hcorice root fibers. 

Fig 1 shows the bonding surface of MAFTEX as it appears through the lens of a powerful microscope Note the 
wiry, elastic, strengthening, licorice root fibers forming cave-like pits, hollows, and peaks, as they twist and turn and in- 
terlace. These make the MAFTEX bond. 

Fie 2— taken with the back of the MAFTEX scraped away almost to the bonding union— shows how plaster pene- 
u^tes among the fibers, to key deep into the bonding surface, in and around and back of each tiny root fiber, forming 
millions of mechanical bonds that even repeated tests of 1,000 lbs pull to the square foot fail to loosen. 
Bonding strength such as this might aptly be compared to xhe welding ot metal. 



[10] 




MAFTHX used for entire roof insulation— Eton Hall Apartment, Scarsdale, N. Y.; 
Bagge-Murray Co., New York City, builders. 



CHAPTER II 



General Applications 
of 




There are of course many uses for MAFTEX in various types of con- 
struction, a few of which are explained in the following pages. 



1. Roof Sheathing 

MAFTEX replaces wood sheathing under the 
usual roofing materials and provides insulating 
value as well. 

2. Side Wall Sheathing 

On side walls MAFTEX is used in place of 
ordinary sheathing, thereby providing added 
strength and adequate insulation. 

3. Plaster Base 

MAF-LATH (which is made exactly the same 
as MAFTEX, but of a different size) replaces 
wood lath, metal lath or plaster board on walls 



and ceilings. It provides a bonding surface of 
tremendous strength as well as preventing trans- 
mission of heat and sound. 



. Sound Deadening 

MAFTEX, when used in partitions and floors, 
provides unusually effective sound-deadening. 

Wall Finish 

The rippled surface of MAFTEX forms an at- 
tractive finish in itself — and produces particularly 
beautiful effects when paints and stains are used 
on MAFTEX paneling. 



[11] 



Wood SHiwdLfcs 

Maptetx- 




~5tr.ip3 



Wood 
5HIN0Lt3 



Af^rex 



Wood Siding on Wood 

Framing 

Western Frame 

Construction 

ROOF construction. MAFTEX 
applied direct to wood rafters 
with strips nailed on top 
through the MAFTEX to each 
rafter. Wood shingles nailed to 
strips. Eaves open with under- 
side of MAFTEX painted or 
stained like adjoining wood- 
work. 

OUTSIDE of exterior wall. 
MAFTEX applied direct to 
wood studs, headers and fram- 
ing. Wood siding laid over 
MAFTEX and nailed through to 
each stud. The replacement of 
sheathing by MAFTEX elimi- 
nates the necessity of using 
building paper and adds thermal- 
insulation. 

INSIDE of exterior wall. MAFTEX nailed direct to wood 
studs and headers with wood mouldings covering the joints 
and forming panels. The same finish is used for the 
CEILINGS, SOFFITS and INTERIOR PARTITIONS. 

FLOOR construction. First story, MAFTEX installed be- 
tween rough and finished wood floors for thermal-insulation 
and to hush cellar sounds. Second story, same flooring 
method for sound deadening results. 




Wood Shingles on 

Wood Framing 

Balloon Frame 

Construction 

|y|^^^^^ ROOF construction. MAF- 
TEX applied direct to 
wood rafters with strips nailed 
on top through the MAFTEX 
to each rafter. Wood shingles 
nailed to strips. 

OUTSIDE of exterior wall. 
MAFTEX applied direct to 
wood studs and framing with 
strips nailed through the MAF- 
TEX to each wood stud. Wood 
shingles nailed to strips. Build- 
ing paper eliminated. 
INSIDE of exterior wall. MAF- 
LATH nailed direct to wood 
studs, ribbons and headers and 
plastered with gypsum plaster, in 
accordance with the Basic Methods of Application, to afford 
thermal-insulation and ser\^e as plaster base. Same method 
for CEILING, SOFFITS and INTERIOR PARTITIONS. 
FLOOR construction. First story, MAFTEX installed be- 
tween the rough and finished wood floors for thermal- 
insulation and "to hush sounds from cellar. Second story, 
same flooring method for sound deadening results. Attic 
floor MAFTEXED for added thermahinsulation (and to 
hush attic sounds, if floored and used) . 



[12] 



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Stucco on Wood 

Framing 

Balloon Frame 

Construction 

ROOF construction. MAF- 

TEX applied direct to 

wood rafters with strips 

nailed on top through the 

MAFTEX to each rafter. 

Asbestos shingles nailed to MA^TErX- 

strips. 

OUTSIDE of exterior 
wall. MAFTEX applied 
direct to wood studs and 
framing with strips nailed 
through the MAFTEX to 
each wood stud. Metal 
lath nailed to strips. Stuc- 
co applied to metal lath. 

INSIDE of exterior wall. MAF-LATH nailed direct to 
wood studs, ribbons and headers and plastered with gypsum 
plaster, in accordance with Basic Methods of Application, 
to afford thermal-insulation and serve as plaster base. Same 
method for CEILINGS, SOFFITS and INTERIOR PAR- 
TITIONS. 

FLOOR construaion. First story, MAFTEX installed be- 
tween the rough and finished wood floors for thermal- 
insulation and to hush sounds from cellar. Second story, 
same flooring method for sound deadening results. Attic 
floor MAFTEXED for added thermal-insulation and to 
hush attic sounds. 




Metal Roo^iN<^ 

SHtATHlNCi 

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Brick Veneer on Wood 

Framing 

Balloon Frame 

Construction 

ROOF construction. MAFTEX 
applied direct to wood rafters. 
Sheathing nailed on top through 
the MAFTEX to each rafter. 
Metal roofing fastened to sheath- 
ing. 

OUTSIDE of exterior wall. 
MAFTEX applied direct to wood 
studs and framing. Metal ties 
for brickwork nailed through 
MAFTEX to studs. Brick veneer 
erected as outside finish of wall. 

INSIDE of exterior wall. MAF- 
.LATH nailed direct to wood 

studs, ribbons and headers and 
plastered with gypsum plaster to afford thermal-insulation 
and serve as plaster base. MAF-LATH as plaster base in 
basement nailed to furring strips against masonry wall. 

CEILINGS, SOFFITS and INTERIOR PARTITIONS. 
Same finish as inside of exterior wall above basement. Ceil- 
ing of basement the same. 

FLOOR construction. First story, MAFTEX installed be- 
tween the rough and finished wood floors for added 
thermal-insulation and to hush sounds from basement. 
Second story, same flooring method for sound deadening 
results. Attic floor also MAFTEXED. 




[13] 



5LATE: 
5TRIP5 




CUAYTlLe 

MAfTex 



Brick Wall 

ROOF construction. MAF- 
TEX applied direct to wood 
rafters with strips nailed on 
top through the MAFTEX to 
each rafter. Slates nailed to 
strips. 

EXTERIOR WALL, 
solid. 

INSIDE of exterior wall. 
MAF-LATH nailed to wood 
vertical furring strips, with 
cross strips at floor and ceil- 
ings and plastered with gyp- 
sum plaster. MAF-LATH to 
afford thermal-insulation and 
serve as plaster base. 

CEILINGS of first and upper stories. MAF-LATH applied 
direct to joists and headers, as plaster base and plastered 
with gypsum plaster. All soffits and interior partitions, 
MAF-LATH applied to studs and framing as plaster base 
and plastered same as inside of exterior walls. 

FLOOR construction. First story, MAFTEX installed be- 
tween the rough and finished wood floors for thermal- 
insulation and to hush sounds from cellar. Second story, 
same flooring methods for sound deadening results. 




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M»p 



'MAPTtX- 
JOJST 



ZZZTTZZZTpZ^ 



&Z2S! 



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Plaster. 



Hollow Tile Wall 

ROOF construction. MAF- 
TEX applied direct to wood 
rafters with strips nailed on 
top through the MAFTEX to 
each rafter. Clay tiles nailed 
to strips. 

OUTSIDE of exterior wall. 
Stucco applied direct to Hol- 
low Building Tile. 
INSIDE of exterior wall. 
MAF-LATH nailed to wood 
vertical furring strips with 
cross strips at floors and ceil- 
ings and plastered with gyp- 
sum plaster. MAF-LATH to 
afford thermal-insulation and 
serve as plaster base. 

CEILINGS. MAFTEX applied direct to joists and headers 
of cellar, without plaster, as added insulation. Ceilings of 
first and upper stories. MAF-LATH applied direct to joists 
and headers, as plaster base, and plastered with gypsum 
plaster. All sofl&ts and interior partitions, MAF-LATH ap- 
plied as plaster base and plastered same as ceilings. 

FLOOR construction. First story, MAFTEX installed be- 
tween the rough and finished wood floors for thermal- 
insulation and to hush sounds from cellar. Second story, 
same flooring methods for sound deadening results. 



[14] 




MAFTEX used for entire roof insulation in fine Philadelphia residence. 
H. Louis Duhring, Philadelphia, Pa., Architect. 



CHAPTER III 



For Sheathing on Walls and Sloping Roofs 



Value of Sheathing 

STRICTLY speaking, there are two fundamental 
purposes of sheathing — for structural and for 
insulation values. In the first case the sheathing 
braces and stiffens the framework of the structure. 
In the second case it reduces the leakage of air into 
the building and the transmission of heat through 
the walls. 

Insulating Value 

In this connection it is interesting to note the 
statement that relatively less coal is burned in the 
northern states where winters are long and severe 
than in many of the southern states in which the 
cold season is short and mild. This condition is 
accounted for by the fact that buildings in the north 
are constructed to prevent air leakage and heat 
transmission, while in the south these factors have 
been neglected. 

The United States Bureau of Standards has stated 
that one-half inch of insulation (having the same 
coefficient as MAFTEX) added to the roof and 
walls of the usual forms of construction may be 



assumed to cause from 20 to 30 per cent saving in 
fuel in dwelling houses. 

Tests also show that MAFTEX sheathed build- 
ings are many degrees cooler in the summer. 

Structural Value 

The structural value of sheathing necessarily 
differs greatly in the construction of a wood frame 
building from that of a steel skeleton. With the 
wood frame the sheathing acts as an integral part 
of the structural support, stiffening and bracing the 
wood studs, joists and rafters — while in the steel 
skeleton the framework is not only self-supporting 
but the brick, stone or other materials used as a 
wall filling or coating are carried by the steel and 
therefore need not be of value structurally. 

Horizontal vs. Diagonal Sheathing 

Since this structural strength of sheathing is of 
such importance, it is essential to apply it in the most 
efficient manner. Many architects and builders have 
gone to the added expense of having sheathing laid 
diagonally across the studs. This undoubtedly in- 



[in 



A. MAFTEX used as Sheath- 
ing under wood siding. 

B. MAFTEX used as Roof 
Sheathing under wood 
shingles ( note nailing 
strips). 



creases the bracing strength in one direction on each 
side of the building — but actual tests have shown 
that the distortion due to shrinkage of diagonal 
sheathing is considerably greater than from hori- 
zontal sheathing. This is an especially important 
factor in stucco finished houses as such shrinkage is 
largely responsible for cracks and other damage. 

Horizontal Sheathing Recommended 

In 1915 and 1916 an elaborate series of stucco 
test panels was erected at the Bureau of Standards 
for the purpose of testing different types of stucco 
and stucco backgrounds. As the result of these 
tests it was proved conclusively that sheathing back 
of stucco should be laid hori- 
zontally and not diagonally. In 
1920 the Committee on Treat- 
ment of Concrete Surfaces of 
the American Concrete Insti- 
tute, in formulating its '*Stand- 
ard Recommended Practice for 
Portland Cement Stucco," stated 
the following in support of its 
recommendations that wood 
sheathing should be laid hori- 
zontally. 





MAFTEX used on under side of roof as insulation 

and interior finish on Middletown Air Depot, 

Middletown, Pa. 

[16] 



C. MAFTEX used as Sheath- 
ing under brick veneer. 

D. MAFTEX used as Sheath- 
ing under stucco. 



Recommended Practice 

In sheathed construction the sheathing hoards 
should not be less than 6 inches nor more than 8 
inches wide^ dressed on one or both sides to a uni- 
form thickness of 13/16 inch. They should be laid 
horizontally across the tvall studs and fastened with 
not less than two 8d nails at each stud. 

Notes 

When sheathing is used, it should be laid hori- 
zontally and not diagonally across the studs. The 
stucco test panels erected at the Bureau of Standards 
in 1915 and I916 have demonstrated conclusively 
that diagonal sheathing tends to crack the overlying 
stucco by setting up strains in the supporting frame. 
This result is undoubtedly due 
to the shrinkage of the sheath- 
ing, and whatever benefit might 
be anticipated from the more 
effective bracing provided by 
diagonal sheathing appears to 
be more than offset by the 
shrinkage effect. Diagonal 
sheathing is also less eco- 
nomical than horizontal 
sheathing, both in material and 
labor. 



Directions for Application of MAFTEX 
As Sloping Roof and Wall Sheathing 



The standard basic method of applying MAFTEX 
for sheathing to studding and sloping rafters is the 
same in all cases. When MAFTEX is to be used 
for certain other purposes, the basic methods of ap- 
plication for sheathing still hold good, but there are 
sometimes other points which must also be given 
consideration. These are described in the additional 
directions which follow after the "Basic Method" is 
outlined. 



Basic Method of Application 

General Notes 

These directions are based upon MAFTEX being 
applied "direct" to the exterior of studs and sloping 
rafters, replacing the ordinary sheathing or roofing 
boards. Experience and tests show that the struc- 
tural strength and waterproofness of MAFTEX 
render unnecessary the use of sheathing or roofing 
boards and building paper or roofing paper. (See 
separate directions for applying various side wall 
or roof coverings over MAFTEX.) Wherever it may 
be desired, however, to apply MAFTEX as supple- 
mental to sheathing or roofing boards, it will only 
be necessary to use ordinary 1 inch nails sparsely 
driven (nailing the center of the sheet first) to keep 
the boards in place until the side wail or roofing 
material is applied. 

Notes as to Frstming 

Ail framing, such as studs (or furring strips), 
joists, and rafters for sloping roofs should be set 
in the usual manner and accurately spaced 16 inch 
on centers. At top and bottom ends of MAFTEX or 



wherever joints occur between sheets on studded 
walls, 2x4 inch headers should be nailed between 
the studding. The faces of studs, headers and rafters 
and the bottom of joists should be true and even. 

• 

Application 

MAFTEX on the studding should be applied with 
the long dimension parallel to the framing and 
should have a solid bearing under all edges. 

MAFTEX on the rafters of sloping roofs should 
be applied with the length of the sheets crossing 
the rafters. No headers are required at the cross 
joints as the stripping for the roofing material may 
occur over the joints thus closing them. When the 
stripping does not cover the joints, an extra strip 
should be inserted for this purpose. 

Always allow 1^ i^^^"* clearance between boards 
at both ends and sides. The boards should never 
be forced against each other to fit into place. Where 
a tight joint is desirable with other materials, as 
around door frames, window frames, eaves and 
similar locations, the MAFTEX should be brought 
into close contact. 

For nailing MAFTEX use large-head galvanized 
'^roofing" nails l]/^, inch in length. Beginning at the 
top or one end drive nails down the intermediate 
studs, joists, rafters or furring strips, spacing the nails 
6 inches apart. Follow by nailing the top edge, bot- 
tom edge and last of all the side edges. Along all 
edges, the nails should be placed 4 inches apart and 
% inch from the edge. The nails should be driven 
until the head is slightly below the surface of the 
board. 



[17] 



special Notes 



Although the application of MAFTEX as sheath- 
ing for either sloping roofs or wall surfaces is a 
simple matter as described in the Basic Directions 
on Page 17, there are certain points in connection 
with its use in various locations and under various 
materials which should be emphasized. 

Sloping Roof Sheathing 

One of the most important sources of heat loss 
from the average residence is the roof. Heated air 
rises and if, when it has passed through the lower 
ceilings and floors and reaches the roof, it does not 
meet with some obstruction, it will naturally pass 
to the outside air and its value will be lost to that 
house. This fact can readily be appreciated by 
noticing how fast the snow melts on the roof of the 
heated but uninsulated house in comparison with 
that on the roof of an insulated house. 



— for Wood Shingles 

The illustrations clearly indicate the manner in 
which MAFTEX should be applied to the roof 
rafters. In the first drawing the MAFTEX is laid 
directly on top of the rafters and nailed to them in 
accordance with the Basic Directions. On top of the 
MAFTEX, and nailed through it to the rafters, are 
placed the ordinary shingle lath. These should be 
spaced to suit the "weathering" of the shingles. 
Where stripping does not cover cross joints an extra 
strip should be inserted for this purpose. The wood 
shingles are then nailed directly to the strips. It will 
be noticed that the MAFTEX extends out on the 
underside of the open eaves. Where so exposed it 
may be painted or stained like the adjoining wood- 
work. 

The second drawing shows the usual wood sheath- 
ing applied on top of the MAFTEX as a base for 
the metal roofing. When this method is rsed, the 
nails for the sheathing should be a half inch longer 
than those ordinarily used to allow for the thickness 
of the MAFTEX. . 




Method of applying MAFTEX to roofs under wood shingles and to side walls 

under siding. 



[18] 




Method of applying MAFTEX to roof under sheathing and to side walls under 

wood shingles. 



■ — for Other Roofing Units 

For slate, clay tile or asbestos sliingles the same 
method of applying shingle lath on top of the 
MAFTEX may be used as is shown for wood 
shingles. Of course, the lath should be properly 
spaced to accommodate the roofing materials. 

If there is any prospect of delay or waiting for the 
slate, tile or other roofing materials after the MAF- 
TEX has been laid on the roof, it is advisable to 
cover the MAFTEX with roofer's felt as would be 
done in the case of wood sheathing. 

MAFTEX on Old Buildings 

Although not shown in any of the drawings, 
MAFTEX may be used for insulating the roofs of 
old buildings by applying the boards on the under- 
side of the rafters. The MAFTEX should be brought 
into close contact with the side wall sheathing or 
insulation and all possible points of air leakage 
covered. This is especially necessary around the 
eaves. 



Wall Sheathing 

In applying MAFTEX as wall sheathing in place 
of wood under siding, shingles, stucco or brick 
veneer the Basic Directions give the essentials of 
the method of application. The following, however, 
calls attention to certain details shown on the above 
drawing and many of the same points will be noted 
on the drawings on the succeeding pages. The first 
will therefore be discussed in detail and the others 
only where they differ from this drawing. 

MAFTEX Under Siding 

In examining the drawing several interesting 
points will be noted. First, that the MAFTEX forms 
a close contact with the top of the foundation wall 
and the bottom nailing is into the sill of the struc- 
ture. The header joist above the sill furnishes a sub- 
stantial nailing and the rough floor runs through on 
top of this. The sill on top of the rough floor and 
the studs, 16 inches on centers, above are sheathed 
with MAFTEX in accordance with Basic Directions 
on Page 17. 



C19] 



MAFTEX Around Window Boxes 

As one of the most important sources of air leak- 
age is around the window boxes, special attention is 
called to the construction and the method of installa- 
tion of MAFTEX at this point. It will be noted that 
the MAFTEX is carried up closely under the sill, 
the headers furnishing the proper base for nailing. 
On the jambs MAFTEX is carried closely up to the 
box and nailed to the doubled studs. Here it is run 
back of the exterior window trim to secure an ab- 
solutely tight and airproof joint. At the head the 
MAFTEX is carried down back of the exterior head 
or drip moulding and up against the box member 
and nailed to the doubled headers. 





•M\F-LATH 



Molding 



^5lLL 



Method of applying MAFTEX on side walls under 
clapboards. 



Applying Siding 

In applying the siding all 
joints must come over the 
studs to provide a secure nail- 
ing and nails -[/^ inch longer 
than usual should be used to 
allow for the thickness of the 
MAFTEX. 



Where open eaves are used 
it is important that the MAF- 
TEX be run up to form a 
close contact with the under- 
side of the roof construction 
as this is one of the greatest 
sources of inleakage of air which has a cooling 
effect upon the whole structure. The MAFTEX 
should be cut in between the rafters to form a close 
joint with the roof sheathing and the plate. Small 
blocks of wood are nailed to the sides of each rafter 
to provide nailing for the MAFTEX. 



MAFTEX Under Wood Shingles 

When MAFTEX is used in place of wood sheath- 
ing under wood shingles, the MAFTEX is applied in 
the usual way as described in the Basic Directions 
on Page 17. This is shown on the isometric drawing 
on Page 19. It is important to see that it is nailed 
in accordance with the instructions and that it is run 
closely around the window boxes and door frames 
to prevent as much air leakage at these points as 
possible. 

On top of the MAFTEX shingle lath should be 
placed and nailed through the MAFTEX to each 
stud. The spacing of the strips should be such that 
it will suit the "weathering" of the shingles. The 
shingles may then be applied in the usual manner. 



MAFTEX Under Stucco 

In the first drawing on Page 21, MAFTEX is used 
in place of wood sheathing back of the metal lath 
and stucco. Follow the Basic Directions for the 
application of MAFTEX as printed on Page 17 and 
see that the MAFTEX is carried closely against 
the window boxes and door frames. 



[20] 



Over the MAFTEX apply furring strips nailed 
through to each stud. The strips should be placed 
properly to accommodate the lath to be used. The 
lath can then be applied to the strips and the stucco 
applied in the customary manner. If self-furring lath 
is used the furring strips are not required. 

MAFTEX Under Brick Veneer 

When MAFTEX is used in place of wood sheath- 
ing under Brick Veneer, it is applied to the wood 
frame in the usual manner as described in the Basic 



Directions on Page 17. The MAFTEX should be 
carried closely against the wood sill and the window 
box. 

Metal ties or anchors for the brickwork are nailed 
through the MAFTEX to the studs at proper inter- 
vals to meet the brick courses. The brick veneer can 
then be erected as the outside finish of the wall in 
the customary way. 

The MAFTEX should be run to the bottom of the 
roof construction to provide against air leakage. 





Method of applying MAFTEX on side walls under 
metal lath and stucco. 



Method of applying MAFTEX on side walls under 
brick veneer. 



[21) 




Stanwood Phillips, New York, architect. 



R. Bruce Munro, Rye, N. Y., architect. 



Two beautiful MAFTEXED homes on grounds of Westchester-Biltmore Country Club, Rye, New York. 
H. S. Stevens Co., Inc., Rye, N. Y., builders. 




MAFTEX used as sheathing under brick veneer. 



MAFTEX used as wall sheathing under stucco. 



f 



Two residences in White Plains, N. Y. 
George W. Osterhoudt, White Plains, N. Y., architect and builder. 

The two lower homes, which are typical of moderate priced building operations, well illustrate the fact 
that MAFTEX can be economically installed on contracts where material and construction costs are of 

primary consideration. 



1 



[22] 




MAFTEX used as interior finish, painted, in Scott Hotel, Oquaga Lake, N. Y. 
Conrad and Cummings, Architects, Binghaxnton, N. Y. 



CHAPTER IV 



For Interior Decoration 



EVERY architect is sure to encounter situations 
which call for paneled treatments. Usually, of 
course, decorative effect is the principal ob- 
jective, but there are other points to be considered 
in the choice of material employed. 

Other Factors Considered 

Insulation is one important point. Appreciation 
of the value of heat-proofing for interior walls and 
ceilings, as well as the exterior, naturally demands 
that paneling combine effective insulation with dec- 
orative surface quality. 

Sound deadening is also important. Interior walls 
and ceilings that hush room-to-room sounds play 
a part appreciated quite as much as insulation. 
There is a decided advantage in paneling that effec- 
tively accomplishes this. 

Endurance is still another point. Not only must 
the material have the desired texture and satisfying 



natural color; there should also be assurance of 
permanent rigidity, absence of curvature, buckling 
or distortion caused by thermal changes, vibration, 
and the normal contractions and expansions to 
which the structural elements of all buildings are 
more or less subjected should be minimized. 

Further, there must be a high degree of resistance 
to atmospheric change, the effects of time, and the 
depredations of rats, mice and other vermin. 

With all these qualities the board selected for 
interior decorative effects must be thoroughly "work- 
able*' — must be easy to handle, quick and efficient 
in its application, permit clean-edged saw cuts and 
solid nailing. 

MAFTEX "Thermal-Insulating" Board fulfills 
each of these requirements and at the same time 
produces a pleasing gray-brown color and interesting 
ripple bonding surface that adapts itself so well to 
natural effects or applications of paint or surfacing 
compounds. 



[23] 



Decorative Effects With 



For Interior Use 

THE possibilities of 
using MAFTEX 
"Thermal-Insulating" 
Board to secure decorative 
effects on the interiors of 
residences, apartments, 
offices and practically all 
types of structures are, in 
a sense, limited only by 
the originality of the de- 
signer or decorator. Every 
structure, and in fact 
every room, is in itself a 
distinct and separate prob- 
lem — and should be so 
treated by the decorator. 

In some cases the 
boards may be left un- 
treated, with their pleas- 
ing gray-brown surface ex- 
posed. This is economical 
and the neutral color of 
the boards furnishes a 
most satisfactory back- 
ground for pictures and 
wall draperies. MAFTEX 
is usually paneled by ap- 
plying strips of wood, or 
battens, over the joints 
and painting them to har- 
monize with the natural 
tone of the board. This 
treatment provides an in- 
expensive but most effec- 
tive result. 




Fig. 3. MAFTEX paneling with natural rippled surface left un- 
finished. Molded battens of wood cover the vertical joints and 
miter with horizontal wood member at ceiling angle and bottom 
horizontal wood member on top of baseboard, forming large panels 
the full width of MAFTEX, or three studding spaces, and the full 
height of room. The ceiling shows MAFTEX applied direct to 
the joists and plastered. 



As a modification of this method, the MAFTEX 
may be colored with paint, stain or kalsomine. When 
this scheme is adopted, battens or strips of wood 
may be colored to match or harmonize with the 
color used on the MAFTEX. 

Stenciling with stains is a most pleasing variation 
of this method. Unusual and surprisingly beautiful 
eflfects can be secured with an ultimate result much 
like that of Japanese Grass Paper. The neutral back- 
ground of the MAFTEX, when treated with stencil 
stains, allows the fiber structure of the board to show 
through and gives a soft and slightly "blurry" effect 
which is most attractive. 



Special Surface 
Coatings 

One of the latest devel- 
opments in the field of in- 
terior decoration is the ap- 
plication of special sur- 
face coatings for smooth 
or textural effects on walls 
and ceilings. 

These give most satis- 
factory results when ap- 
plied to MAFTEX, form- 
ing a bond of unusual 
strength and endurance, 
as well as a surface that 
may be textured in any 
number of ways in accord- 
ance with the directions of 
the manufacturers. 

MAFTEX also forms 
an excellent base for all 
types of wall coverings. 

MAFTEX provides not 
only an excellent decora- 
tive material but also one 
which will provide a high 
degree of thermal-insula- 
tion. The strength of 
MAFTEX has been 
proven superior to that of 
wood sheathing in its re- 
sistance to twisting and 
distortion, and its use 
adds rigidity and stiflfness 
to any structure. 



For Exterior Use 



MAFTEX "Thermal-Insulating" Board can be 
used successfully as an interior-exterior wall material 
for certain types of smaller structures — camps, sum- 
mer bungalows, etc. — where insulation, interior 
attractiveness, and economy are factors. 

For this use MAFTEX boards may be applied 
directly, and exposed, upon outside studs, with 
outside surfaces painted and interior surfaces treated 
in the manner described. 



k 



(241 



Paneled Walls and Ceilings of MAFTEX 



IN its original form, paneling was actually half- 
timber construction. Framing of this character 
was of massive posts and rails, usually molded, 
and the panels were let into the framing. 

Gradually the framing became of less and less 
structural value and was reduced in thickness. The 
panels were also reduced to a more convenient size. 
About 1650, when Inigo Jones designed his famous 
masterpieces, there was a remarkable change, large 
panels made up of several boards being glued to- 
gether.* Three styles of paneling are common today 
— namely, English, French and Colonial. Each has, 
of course, many variations but in the broadest sense 
these may be said to be the most popular general 
types. 



Present day paneling, although it follows in design 
and effect the rules laid down by precedent, is seldom 
constructed entirely of wood and almost never with 
the structural members exposed. Under modern con- 
ditions the use of MAFTEX "Thermal-Insulating" 
Board for paneled effects has become increasingly 
popular. And this is quite natural, for MAFTEX 
combines not only strength, rigidity and a high 
degree of heat savings in one material, but also 
assures pleasing and satisfactory surface decorative 
effects. 

Important Principles 

In applying MAFTEX as paneling there are a few 
important principles which should be borne in mind. 




\ 



ElE VAT I O N 



5ECTION 




Fig. 4. MAFTBX applied directly to face of studs from floor to ceiling, thus insuring full insulation. Wood paneling is placed on the 
MAFTEX to the usual height of a chair rail, which may or may not correspond with height of window sills. The MAFTEX on upper 
portion of wall has wood battens over vertical joints mitering with horizontal wood members at top of wainscoting and at ceiling angle. 
The vertical lines of nailing on intermediate studs may be left with heads exposed or hidden from view, as described on following pages, 
depending on finished effect desired. The section and details at the side show MAFTEX used on the ceiling and under finished floor — for 

decorative effect and sound-deadening combined. 

*For an excellent discussion of the development of Paneling see "A Short History of the Building Crafts" by Martin S. Briggs, F. R. I. 

B. A.J upon which the above is based. 



[25] 




Fig. 5. MAFTEX used for long, narrow panels extending uninter- 
ruptedly from floor to ceiling, with molded wood battens not only 
over vertical joints but over each vertical line of nailing on inter- 
mediate studs, thus covering nail heads completely. The molded 
battens miter with the horizontal moldings at ceiling angle and 
baseboard, all woodwork and the MAFTEX being finished with 
oil paint of contrasting colors. The ceiling joists are left exposed 
with the MAFTEX under the floor above showing 
between the joists. 

These are discussed below and the points brought 
out will prove of assistance to anyone contemplat- 
ing this type of decoration. 

Framing 

A paneled wall is essentially made up of divisions 
of surface, which are emphasized by the application 
of moldings or battens. These battens may or may 
not be only those which cover the joints between the 
MAFTEX boards, but in any case they must have a 
secure nailing. It is, therefore, most important that 
the design and layout of the panels be determined 
before the studs are set, so that they may occur be- 
hind the molding. If, for any reason, this cannot be 
done, it will be necessary to insert extra studs or 



nailing pieces to provide a nailing base. Wherever 
there may be danger of unusual pressure of 
blows against the panels, as at chair rails, reinforc- 
ing headers should be inserted. Of course it is 
desirable according to expected occurrence of such 
jars to provide a "rail" in the paneling at that height. 
Studs should never be placed more than 16 inches 
apart on centers, and any studs which are not straight 
and true should be made so by wedging or other 
means. In planning the arrangement of the studs, 
it should be borne in mind that MAFTEX boards 
are cut a scant 4 feet in width to allow l/^'^ spacing 
between sheets. 

Application of MAFTEX 

The MAFTEX should be moistened evenly, using 
about one quart of water to each side of every 4 by 
8 feet of board. This wetting should be done 24 
hours before the boards are to be used. Apply the 
boards with the long dimension parallel to the fram- 
ing and be sure that there is ample nailing space 
along all edges. The board should never be forced 
to fit, but a space of y^ inch should be left between 
all edges. 

Nailing 

Nail the boards to the intermediate studs or other 
framing first, using either box nails or lather's nails, 
II4 inches long, spaced 4 inches apart, driven 
straight; or finishing nails l]/^ inches long, driven at 
a slight angle for all exposed nailing. All edges 
which are to be covered with battens should be 




EIlE VATIO N 5e:CT ION 

Fig. 6. MAFTEX and wood battens applied in a somewhat 

similar manner to Fig. 5, thus insuring full insulation, but with 

the addition of a wider horizontal batten at chair rail height. 

The ceiling would have similar battens at joints. 



[26] 



/ 





Ele vat I O N 



5ect ion 




Fig. 7. One of the simplest forms of use for MAFTEX. The boards are appHed direct to face of studs from floor to ceiling, thus insuring 
full insulation, with panels formed by using plain battens of wood or MAFTEX to cover vertical joints. A MAFTEX strip is placed at 
ceiling angle with wood crown molding and at floor a beveled wood base with wood quarter-round is used. The section and details at the 
side show the methods of construction and indicate MAFTEX on the ceiling for decorative effect and for sound-deadening from above 
and MAFTEX under the finished floor for sound-deadening from below. The intermediate nail heads may either be "set" and puttied for 

painting or staining or be concealed by "flaps" as described on this page. 



nailed with the same box nails or lather*s nails, 
although large-headed galvanized roofing nails ll^ 
inches in length may be used if desired. These 
should, in either case, be spaced about 3'' to 4'' 
apart and %''' in from the edges. 

Nailing Concealed by Flaps 

Where it is desired to secure an unbroken plane 
of wall or ceiling, the heads of nails may be con- 
cealed by gouging up a thin flap of the surface at 
each nailing point, setting the nails below the flaps, 
and pasting down flaps over the nail heads with col- 
orless glue, cement or other suitable adhesive. 

Battens 

The battens may be made any width desired, de- 
pending upon the type of paneling and other factors. 
Ordinarily these will be of wood, but strips of MAF- 
TEX from T^ to V^ wide will be found very satis- 
factory if the edges are slightly rounded or beveled 
with fine sandpaper or with special tools that may 
be obtained for this purpose. The battens should be 
nailed through the MAFTEX into the studs, using 
214^' finishing nails driven at an angle. If the 
battens are of wood, the nails should be set and the 
holes treated in the usual manner with putty before 
painting, or the concealed flap method, described 
above, may be employed. 



Fainting or Staining 

AS PREVIOUSLY stated, MAFTEX is manu- 
/\ factured in a pleasing neutral tone, and for cer- 
tain purposes and surroundings the natural color will 
furnish an efi^ective background, only wood battens 
being painted or stained. Painting and staining of 
the surface is described below, for those who desire 
this type of finish. 




ElE VATI ON 



Sect io.n 



Fig. S. A variation of Fig. 7 with MAFTEX used diiectly over 
studs and vertical joints covered with strips, or battens, of MAF- 
TEX. The horizontal pieces of MAFTEX at top and bottom are 
supplemented with a wood molding at ceiling and a wood base- 
board. The ceiling would have similar "battens" of MAFTEX 
over the joints. 



C27] 




Maftex- 



Eleivation Section 



PLAN 

Fig. 9. A type of construction developed for summer cottages, 
clubs, etc, MAFTEX, cut to the width required, is placed midway 
between the studs and held in place with wood moldings fastened 
direct to the studs on each side of the MAFTEX. This means only 
one line of separation between rooms instead of the usual two 
thicknesses when plastered or boarded on both faces of studs, but 
gives an economical and effective result. The ceiling would consist 
of exposed joists with the MAFTEX under the flooring above 
showing, as illustrated in Fig. 5. 



Painting 

Ordinary lead and oil paints may be applied sat- 
isfactorily to MAFTEX without sizing or priming. 
Two coat work is advised for the most effective re- 
sults. 

Where battens are to be used with the MAFTEX 
surface painted, the first coat should be applied be- 
fore battens are put in place, thus obviating all pos- 
sibility of an unpainted line being exposed at the 
edge of the batten. 

Plastic Paint 

Directions are not given here for the application 
of plastic paints, as the mixes and methods will vary 
with each individual manufacturer. In general, 
plastic paints consist of a dry powder which is mixed 
with water to a specified consistency and applied to 
the MAFTEX with a wide brush. These paints may 
be given almost any type of textural finish in accord- 
ance with the directions of the manufacturer. 

Usually these paints are white and are painted or 
stenciled after application to the wall. When it is 
desired to have a uniform color, pigments may be 
mixed with the paint before application. 



Staining 

Staining with the ordinary commercial stains will 
prove perfectly satisfactory on MAFTEX, providing 
the manufacturer's directions are followed. Any 
color or combination of colors which will prove har- 
monious with the decorative scheme may be used. 
Stencil efifects, employing the natural tone of the 
MAFTEX as a background, give all the pleasing 
results of grass paper and most unusual and attrac- 
tive treatments may be developed. 

Kalsomining 

When using kalsomine over MAFTEX the sur- 
face should have been sized or ordinary glue size 
must be added to the mixture. Follow the directions 
of the manufacturer in applying the kalsomine, 
which may be stenciled in most pleasing effects if 
desired. 

MAFTEX ^ThermaUnsulating'* Board is 
fabricated in 4 foot wddths and 8, 9, 10 and 12 
foot lengths, 7/16 inch thickness. 




Fig, 10. MAFTEX, in a display room, used for panels similar in 
construction and effect to Fig. 3. The surfaces of the MAFTEX in 
this case have, however, been covered with a plastic finish on the 
left side, with a textural gypsum finish on the center panel and the 
MAFTEX has been left exposed on the right side. 



[28] 




MAFTEX used as a sound deadener (and plaster base) on dividing 
partition walls, Parkway Arms Apt., Larchmont, N. Y. Radding Con- 
struction Co., Larchmont, N. Y., Builders. 



CHAPTER V 



For Sound-Deadening 



A S present-day civilization rapidly progresses, 
^/j^new demands are constantly being made for 
greater refinements in construction — one of 
the most recent being sound-proof construction. 

Popular interest in the subject is so new that many 
have not had the opportunity to familiarize them- 
selves with the principles involved. It is possible, 
however, with a knowledge of the basic principles 
of acoustics and with the aid of the structural ma- 
terials now available, to secure excellent results in 
sound-proofing. 

Characteristics of Sound 

When a sound wave reaches the ear drum, the 
impulses produce alternate compressions and disten- 
sions of the membrane corresponding in frequency 
to the actuating air impulses. The result is the 
sensation of sound. 



Several of the more important characteristics of 
sound should be noted. In the first place, it should 
be clearly understood that sound is a form of en- 
ergy just as truly as heat and electricity. As a result, 
sound waves are capable of imparting motion to 
heavy objects. Actually, the energy of a sound wave 
is very minute, and the amount of motion it may 
cause is therefore slight. 

All sound is not alike, as we know from the range 
of the musical scale. The ''pitch" of a sound or 
musical note depends upon the frequency with which 
the vibrations or waves occur. The human ear is 
sensitive to vibrations occurring with a frequency of 
between ten per second and thirty thousand per 
second. Air impulses occurring less or more fre- 
quently are not heard. 



[29] 



The speed with which sound moves depends 
chiefly upon the medium through which it travels. 
In air the speed is approximately 1/5 of a mile per 
second. Its speed through water is about four times 
as great, and through wood twelve times as great. 



the dense material in the form of a wave just as was 
described in the case of air. A final component trans- 
fers its energy to the structure causing it to vibrate 
like the diaphragm of a loud speaker or the ear 
drum. The vibration of the structure is in turn com- 




MAFTEX being applied for sound deadening (also for interior finish and 

insulation) in Scott Hotel, Oquaga Lake, N. Y. Conrad and Cummings, 

Architects, Binghamton, N. Y. 



Unlike light, sound does not of necessity travel in 
straight lines. It will go "around corners" and 
travel in circuitous routes with little loss in energy. 

As sound progresses from its source its intensity or 
loudness decreases. For example, if we double the 
distance from the source the intensity is somewhat 
less than one quarter as great. 

Thus far we have considered only the transmission 
of sound through air. Were other materials incapa- 
ble of transmitting sound, the problem of sound- 
proofing would be a simple one. It would only be 
necessary to surround the room or structure with an 
air-tight medium, taking care to make the enclosure 
tight. Experience has shown, however, that when 
sound waves strike such a barrier their progress is 
retarded, but not completely stopped. A considera- 
tion of the mechanism of sound transfer under such 
conditions is important if we are to understand 
sound-proofing of building partitions. 

Effect of Sound Waves 

When sound waves strike the surface of an air- 
tight partition several things happen. In the first 
place, a large portion of the incident sound is re- 
flected back in the direction of the source in exactly 
the same way that a mirror reflects light. Another 
portion of the sound energy is conducted through 



municated to the air on the opposite side, reproduc- 
ing sound waves which continue on their way. 

The effect last described is known as diaphrag- 
matic action, and is of a great practical importance in 
sound-proof building construction. The effect is 
greatest in highly elastic materials such as sheet 
steel, glass and hard plaster, particularly if they be 
rigidly supported, but becomes negligible in the case 
of non-elastic materials such as felted fibrous sheets. 

Ideal Sound-Proofing Material 

Having in mind 
the basic princi- 
ples of sound gen- 
eration and trans- 
mission as we 
have outlined 
them, the charac- 
teristics of an ideal 
sound - deadening 
structural material 
may now be con- 
sidered. 



MAFTEX used for 
sound deadening be- 
tween partition walls 
(also for roof insulat- 
ing) in Chateau Lafay- 
ette, Greenwich, Conn. 
E. Gisondi, Inc., 
Mt. Vernon, N. Y., 
Builders. 




[30] 



Fh'Sl — In order to prevent the direct passage 
of sound waves with air as the transmitting 
medium the material should be approximately 
"air-tight." Direct air channels through a 
material will permit the transfer of sound even 
if the courses of the channels are circuitous in 
the extreme. 



the sound impulse is required to pass from one air 
cell to the next there is a considerable energy loss, 
and the rate of "decay" or the "absorption" of the 
sound energy is therefore enormous. 

The elastic characteristics of the sheet are such that 
diaphragmatic action is reduced to a minimum. It 
should be understood, however, that this diaphrag- 



k^m 




' '«11# 




MAFTEX used as a sound deadener in bowling alleys of Moose Home, 

Bridgeton, N. J. 



Second — The material should be reasonably 
thick so that sound waves set up in the material 
itself will "decay" or decrease in intensity in 
passage from one side to the other. 

In MAFTEX we find a particularly satisfactory 
combination of the desirable characteristics of a 
sound-deadening material as enumerated above. The 
closely felted structure of the sheet stops effectively 
the direct transfer of sound impulses by air alone. 

It is true that 
the material con- 
tains innumerable 
air cells, but, to 
pass from one to 
the other the 
sound energy must 
be conducted 
through separat- 
ing walls which 
are poor conduc- 
tors. Every time 



MAFTEX used for sound 
deadening (and for plaster 
base) in Lindy Arms, Mt. 

Vernon, N. Y. 

L. M. Kaufman, New York, 

Architect 




ma tic effect depends largely upon the manner of sup- 
porting the material, and, for this reason, the speci- 
fications given in this chapter should be followed as 
closely as possible. 

Application of 
Sound-Deadening Material 

In order to construct a partition or floor which will 
stop sound transmission, we must, first of all, prevent 
the passage of air waves carrying the sound. Such a 
partition or floor must not only prevent the passage 
of sound through the partition, but should absorb as 
much as possible and not reflect it back into the 
room. Furthermore, the partition must be prevented 
from vibrating to any great extent. 

Experiments have shown that there are several 
ways of constructing a partition which will stop the 
passage of sound. Building thick concrete partition 
walls and floors is one, but this is clearly beyond 
reason because of the weight, cost and the amount 
of space such walls would occupy. We must there- 
fore turn to other materials and methods. 

Characteristics Required 

Consideration of thick concrete construction has, 
however, made apparent the fact that to be prac- 



[31] 



ticable a sound-proof partition must have certain 
characteristics. Among these are: 

(1) A high degree of resistance to sound waves. 

(2) Lightness of weight. 

(3) Reasonable thickness. 

(4) Ease of alteration. 

(5) Reasonable cost. 

(6) Vermin proofness. 

When MAFTEX is used in partitions and floors 
as described on the following pages, the construction 
will possess all the characteristics outlined above as 
essential to a sound-deadened structure. 

MAFTEX Fulfills Requirements 

Why MAFTEX is particularly suitable for this 
purpose is clear if the qualities of the board are 
studied. MAFTEX is a rigid cellular mass having 
high internal sound absorbing quality. It does not 
attract vermin. It will not rot, is economical, service- 
able and labor saving. When wisely installed it may 
be depended upon to produce a high degree of re- 



sistance to sound transmission. Authorities agree 
after most thorough analysis and study that cellular, 
pressed, fibrous boards of the type of MAFTEX 
possess the highest qualities for sound-proofing and 
sound-deadening. 

To provide the most satisfactory results, attention 
should be given also to any other parts of the parti- 
tion or floor which might allow air to leak through. 
These may become important sources of sound trans- 
mission. They will include doors, electric conduits, 
pipes, ventilator ducts and similar equipment. If 
absolute sound-proof results are desired, the doors 
should be of special design or should have a heavy 
solid core. Flush doors with bucks and casings 
should be calked to prevent air leakage. The doors 
should also bear against cushioned rabbet strips and 
the threshhold openings should be closed off with 
automatic strips. 

The following pages offer suggestions for sound- 
deadening construction. 




MAFTEX used as sound-deadener and plaster base in State Normal School, Glassboro, N. J, 

[32] 



Methods of Sound Deadening 



Although there will probably occur a few prob- 
lems of sound-proofing which should be solved by a 
trained engineer, there will be many occasions 
when some suggestions for easy and inexpensive 
methods of sound-deadening will be welcomed. 



of MAFTEX extending under the sill, which in turn 
supports the studs, has a value in that it tends to 
reduce the vibration and the diaphragmatic action 
which is set up in the partition by the action of 
sound striking against it. 



Sound Deadening of 
Partition Construction 

Drawing Number One 

This is the most simple of the various forms of 
construction shown. It will be noted from the draw- 
ing that a layer of MAFTEX is laid on top of the 
rough or sub-floor and on this are placed V^ x y 
sleepers spaced 16'' on centers on which the finished 
floor is laid. In building the partition a T' x 4'' sill 
is laid on top of the MAFTEX and the studs are 
set on this cushioned sill. The studs should be 16'' 
on centers and the MAF-LATH installed in the usual 
manner for a plaster base. This method of sound- 
deadening, although not as efficient as the others 
shown, is easy to install and provides a sound-dead- 
ener for the floor as well as the partition. The layer 



Drawing Number Two 

Next in order of efficiency of sound-deadening is 
the "Staggered Stud" partition shown in the second 
drawing. In various forms this partition has been 
in use for many years. It has two disadvantages — 
namely, that it is more expensive to construct and that 
it occupies more space than the usual partition. In 
the drawing it will be seen that the studs are set on 
a sill which in turn rests on a layer of MAFTEX 
placed on top of the rough floor. The studs are 
placed 16" on centers and there is no through con- 
nection between the two sides of the wall. The studs 
shown are the ordinary 2" x 4" size, but in some 
cases it may be possible to reduce this to 2" x 3", 
depending upon the height of the partition and other 
factors. The plaster is applied directly to the surface 
of the MAF-LATH as described in another chapter. 




2'»2''3TU0S 

Ma^-lath' 
Plaster 



SECTION 



SECTION 



SECTION 



S 



S 



7 

u 



L^ 



3 



a 



E 



'n 



d 



a 



PLAN 

Drawing No. 1 



PLAN 
Drawing No. 2 



PLAN 
Drawing No. 3 






• Gypsum Buock 



{met StAMMM) 



-PLMTCt^ 



Kaftex* BAse 
For Block 



SECTION 



PLAN 
Drawing No. 4 



[33] 



Drawing Number Three 

The most efficient of the three partitions shown 
for use in frame construction is that illustrated in 
the third drawing. Here the form of construction 
is practically the same as that previously shown as 
far as the sill is concerned. Above this is placed a 
double row of T' x T' studs, W on centers. These 
have a V space between them and into this space 
are placed sheets of MAFTEX. These sheets are 
free-standing and loose, not being nailed to any part 
of the construction. To the outside of the studs 
MAF-LATH is applied in the usual manner for plas- 
ter base. Although this partition occupies more 
space than the one shown in Drawing Number One, 
it is comparatively inexpensive and light in weight. 

Drawing Number Four 

The fourth drawing shows a type of construction 
particularly suited to apartment houses, apartment 
hotels, hotels, office buildings and similar structures. 
It illustrates an efficient fire-resistive partition con- 
structed of gypsum blocks. The same principles 
could well be applied to a partition of hollow tile 
and in some cases to a steel stud and metal lath 
partition. Attention is called to the fact that on 
top of the concrete floor a layer of MAFTEX is 
laid as a base for the linoleum floor covering. On 
top of this layer, under the first course of block 
a separate layer of MAFTEX is laid to act as a 
cushion. There are really two separate and entirely 
unconnected partitions with a space of T' between 
them. In this space are placed free standing sheets 
of MAFTEX which perform the same function in 
reducing the sound transmission . as in the partition 
shown in Drawing Number Three. Although V 
gypsum block is shown in the drawing the thickness 
will, of course, depend upon the height and length 
of the partition as well as other factors. 



Sound Deadening of 
Floor Construction 

Drawing Number Five 

In the last analysis, the subject of sound-deadening 
of floors becomes a matter of overcoming impact on 
the floor. In this drawing the MAFTEX is shown 
laid directly on top of the rough floor, with only 
enough nailing to hold the board in place until the 
finished floor can be installed. The finished floor 
is nailed through the MAFTEX into the sub-floor 
and nails long enough to provide a good nailing 
should be used. 



^ 



* 



PlNlSH F-LOOR 

Maftex' 
Rough ?n-oos^ 



■7' Ay J J 



^ ^ ^ L v^ V V v^T 



Floor Joists 



Plaster 
Map- LATH 



^ 




Drawing No. 5 



Drawing Number Six 

The second method of sound-deadening a wood 
joist floor is basically the same as the preceding one. 
It will be noted that the only difference is a second 
layer of MAFTEX which is laid directly on top of 
the joists underneath the rough floor. This increases 
the cushion action and further eliminates the trans- 
mission of impact sounds. 



-F lHlSh F-LOO R 

-Mafteix 
-R OUCH Ploo r 
- Mafte X. 



I i^uuuin I i_u\^»< 

,- MAFTEX. j 



PLOOR Joists 



Plast&r 
Maf-'Lath 



W 




Drawing No. 6 

Drawing Number Seven 

In this drawing there is shown a more elaborate 
method of deadening. The rough floor is laid as 
usual and on top of this is placed a layer of MAF- 
TEX. On top of the MAFTEX and nailed through 
to the joists are placed V x V sleepers. These strips 
run parallel to and on top of the joists and are 
spaced the same, namely 16'' on centers. The 
finished floor is then laid on top of these sleepers 
and securely nailed to them. 

Finish Tuoo^ 




'\ «3" Sleepers -»G o.c. 

Maftek' 

Rough Puoor - 



V V ^ V— ^r-v 



^ ^ ^ ^ "^ 



y /' / 



J jv'j J J rrr^ 



Ploo(^ Joists 



Plastcr — I 

Drawing No. 7 



[34] 



Drawing Niunber Eight 

The method shown in this drawing is probably 
the most efficient of those here illustrated for sound- 
deadening a wood joist construction. It is known 
by various names, but the form remains the same in 
all. The ceiling is entirely separated from the floor, 
independent joists carrying the MAF-LATH which is 
used as a plaster base. The joists supporting the 
floor are set W on centers, a rough floor is laid on 
the joists and MAFTEX on top of this. Sleepers 
V X 3"' are placed on the MAFTEX as previously 
described and the finished floor placed on the 
sleepers. As there are no through connections be- 
tween the floor and ceiling, little sound can pass 
from one side to the other. 



Finish Puoor 




— v'-5" Sleepers M 6."- o,c. - 
Maftetx' 



Pouch Floor -i 



^'y y y ^■: 



rr? 



». 'k V^ 'v-v^V- ^ v.^ ^■k''>->^v.'^^V 



^y ^^^r^ 



222 



Flooi^ Joists 



Ce\uiNG Joists 



Plaster 
Drawing No. 8 



jp^ 



Drawing Number Nine 

For sound-proofing of concrete floors which are 
to be covered with linoleum, the MAFTEX should 
be applied to the concrete in accordance with direc- 
tions. Briefly, these directions call for the concrete 
to be covered with a waterproof primer, the 
MAFTEX to be firmly imbedded in a coating of 
asphaltic cement and the linoleum fastened to the 
MAFTEX with the usual linoleum cement. This will 
provide a cushion which will absorb much of the 
impact caused by foot steps, moving furniture, etc., 
which often cause annoyance. If carpets are to be 
laid on the MAFTEX, nailing strips will of course 
have been inserted and the MAFTEX need not be 
cemented to the concrete. Depending upon condi- 
tions, however, it may be desirable to spot mop the 
concrete just enough to hold the MAFTEX in place. 



n 



LmOLEUM 

MAFTEX 



CONCF^tTt 



Drawing No. 9 



Drawing Number Ten 

If a wood floor is to be laid over the concrete the 
form of construction shown in the tenth drawing 
should be used. The usual T' x y sleepers are 
placed in the concrete and the MAFTEX is nailed 
to these. These sleepers are placed 48" on centers. 
Across these and on top of the MAFTEX are placed 
V X y nailing strips nailed through the MAFTEX 
into the sleepers which are imbedded in the con- 
crete. These strips are spaced 16'' on centers. The 
finished floor is then nailed to these nailing strips. 



■f(Ni5H Floor, 
■l-^a* 5LEtPtR.5 - ic>'* o c. 
r MAFTE-X 

Z\ 2»' 5 L E. fc P E R^S - ^ 6" O. C .- 



Z— 2=ZZ=2=2= 



/ ./^? ^ 1ZZL 



■ ix^' ■•■■ 



; ^' CotsJCF^ET t 



^ 



Drawing No. 10 

Drawing Number EJeven 

In some cases it is desirable to lay linoleum over 
a wood floor and at the same time reduce the sound 
of impact. This condition is shown in the next draw- 
ing. The wood floor should be of matched and 
dressed, tongued and grooved stock and the ends of 
the flooring should be so cut that all joints occur 
over the joists. 

On top of the wood floor lay MAFTEX board, 
nailing each board with 4-penny nails through the 
center and along all edges. The adjoining edges 
should not be forced into contact and the MAFTEX 
should be kept |^'' away from all walls. 

Lay the linoleum in an approved brand of 
linoleum cement over the MAFTEX base in accord- 
ance with the directions of the manufacturer of the 
linoleum. 



LlNOLLUM 



I MAFTtX 

R.0UCH fLOOTL 



i 



^^^^^^^^^^ ^^^^^^^"7 



f LOOIL JoiiTS 



Plkster- 

MaF'-LATH' 




Drawing No. 11 



t35] 



Acoustical Correction 

Thus far we have considered problems relating 
only to sound-deadening — that is, the transfer of 
sound from room to room. 

There is another branch of acoustics which is 
of great practical importance in building construc- 
tion. This relates to the control of sound within a 
single room, and has for its object the suppression of 
echoes and kindred reverberating disturbances. Many 
an expensive and otherwise well-designed structure 
has been thoroughly unsatisfactory for its intended 
use because of disturbing echo effects. 

The reason for the echo is easily explained with 
our present knowledge of sound, and being under- 
stood is readily corrected. The explanation is to be 
found in the fact that ordinary plaster or stone 
surfaces reflect sound almost perfectly. In fact the 
Bureau of Standards is responsible for the statement 
that *' smooth rigid surfaces reflect sound more com- 
pletely than even the best mirrors reflect light.*' 

With this point in mind, and remembering that 
sound takes an appreciable time to travel from one 
point to another, let us consider the predicament of 
one listening to an address in a large auditorium. 



The speaker's voice reaches him and then continues 
to the rear wall of the room, from whence it is 
reflected and, in a fraction of a second, again reaches 
the listener from the opposite direction. By this 
time, however, a new sound is being received directly 
from the speaker and the net result is chaotic. 

Obviously the solution to the problem of Acous- 
tical Correction is to provide walls which will not 
reflect sound. Heavy draperies, thick carpets and 
even members of an audience absorb large amounts 
of sound energy, thus preventing its reflection. In 
many cases, however, additional absorbing surface is 
required to produce proper acoustical characteristics 
in an auditorium. 

It has been found that MAFTEX is particularly 
suitable for acoustical correction in such cases. Mr. 
M. C. Rosenblatt, M. E., Consulting Acoustical 
Engineer of Philadelphia, has made an investigation 
of the sound-absorption characteristics of MAFTEX 
for MacAndrews & Forbes Company. Mr. Rosen- 
blatt has found by careful scientific measurements 
that the Sound-Absorbing Coefficient of MAFTEX 
is 20.16%, which indicates that the product ranks 
very high among sound-absorbing materials and is 
therefore suitable for this type of construction. 



[36] 




MAFTEX PLASTER BASE used in this fine residence, Larchmont, N. Y. 



CHAPTER VI 



As Insulating Plaster Base 



WALLS, partitions and ceilings of today must 
be more than mere divisions of the interior 
of a building into spaces for occupancy or 
other purposes. Conservation of heat in winter and 
its exclusion in summer, the retarding of condensa- 
tion, sound deadening that absorbs and smothers 
the transmission of room-to-room noise, are all fac- 
tors to which modern architects, builders and owners 
are giving the most careful attention. 

To meet these demands by the supplementary ap- 
plication of special materials, involves additional 
time and expenditures for labor and material which 
are rarely justified. 

The solution of the problem of securing these 
desirable results without increased costs, lies in the 
utilization of a material which, while supplanting 
ordinary lathing, will afford a perfect plaster base, 
insulation and sound deadening at one and the same 
time. 



This accomplishment has been made possible 
through the development of MAF-LATH — a perfect 
plaster base combined with insulation and sound 
deadening for modern construction. 

MAF-LATH as a Lathing Material 

While small units or open meshes may first come 
to mind, correctly speaking the term "Lath" is more 
properly applied to any material designed to act 
as a base for plaster. Such lathing material may be 
fastened directly to studs, joists or furring strips 
on masonry. In discussing the subject of plaster 
base or lath the report of the Bureau of Standards 
Plastering Conference published as Circular of the 
Bureau of Standards, No. 151; "Wall Plaster: Its 
Ingredients, Preparation and Properties," states as 
follows: 

"Probably the most important function of lath is 
to hold the scratch coat of plaster in position until 



[37] 



it has had time to harden. It must next display 
sufficient rigidity to prevent the 'key', or mechanical 
bond, of the scratch coat from breaking when the 
brown coat is applied. Finally, it acts as a re- 
inforcing material to distribute any strains which 
may come upon the hardened plaster, thus reducing 
the tendency to crack." 



licorice root fibers. (See Figures and Descriptions 
on Page 10.) This myriad of tentacles becomes 
so imbedded in and around the gypsum ground coat 
that even 1,000 lbs. pull to the square foot cannot 
loosen its vice-like gripping of the plaster. These 
countless mechanical bonds of almost unbelievable 
tenacity and endurance cover every inch of MAF- 




Installing MAF-LATH as plaster base in new home in Stonegate — a beautiful Chicago suburb. 



Until recent years there have been in common use 
only three distinct kinds of lath — wooden, metallic, 
which may in turn be sub-divided into several classes, 
and gypsum plaster board. Now, however, there has 
been placed on the market and at the disposal of 
architects and builders a new material — insulating 
board — which fulfills the three requirements for a 
plaster base mentioned above. A notable material 
in this class is MAF-LATH, which is the same mate- 
rial as MAFTEX, produced in smaller units of size 
especially for lathing purposes. 

MAF-LATH has unusual bonding strength with 
gypsum plaster. This guarantees ability to "hold 
the scratch coat in position until it has had time to 
harden." Furthermore, the rigidity of MAF-LATH 
provides an unusual "reinforcing material to dis- 
tribute any strains which may come upon the hard- 
ened plaster, thus reducing the tendency to crack." 

Cause of the Enduring Plaster Bond 

Micrographic studies of MAF-LATH show its 
bonding surfaces bristling with millions of the tiny 



LATHED wall and ceiling area, insuring the 
strength so essential in the prevention of distortion 
or "breaking away" of the scratch coat when the 
brown coat is applied. 

The interlaced fibrous structure of MAF-LATH 
presents a bonding surface on a resiliently rigid 
material that, when properly nailed to studs, joists 
or furring strips, distributes any strains which may 




MAF-LATH is conveniently packaged 
for ready shipment. 



[38} 



come upon the hardened plaster, thus reducing the 
tendency of cracking, and otherwise protecting the 
finishing coat or any costly surface treatment and 
decoration. 

The Insulation Behind the Bond 

Characteristics of the roots of licorice which give 
to MAF-LATH its high degree of insulating 
efficiency, as well as enduring structural strength, 



in, the Guide of the American Society of Heating 
and Ventilating Engineers. (See page 7.) 

Insulation is a most important consideration for 
any plaster base on the inside of outside walls or on 
ceilings under roofs. A blanket against the escape 
of heat in winter and the entrance of heat in summer 
is furnished by MAF-LATH — a well-worth-while 
result which is obtained without the added expense 



/ 




Applying plaster over MAF-LATH in home at Stonegate, shown on opposite page. 



resiliency, sound deadening and vermin retardant 
qualities, have been referred to in previous chapters. 

In another section of this Manual are given com- 
plete illustrated descriptions of the effectiveness of 
these materials as barriers to thermal conductivity, 
based upon findings authenticated by, and published 




MAF-LATH is of convenient 
size for easy handling. 



for insulation. The Guide of the American Society 
of Heating and Ventilating Engineers is also author- 
ity for the statement that heat transmission for a 
wall constructed of clapboards, paper, wood sheath- 
ing, studs, lath and plaster is 0.227 British thermal 
units per degree difference in temperature between 
the two sides, per hour, per square foot when the 
wind velocity on the exterior of the wall is fifteen 
miles per hour. The same authority states that 
when 1/^ inch of fiber insulation in board form is 
used in place of wood sheathing and wood lath, 
the Coefficient of Transmission is reduced to 0.157 
B.t.u. under the same conditions. This means a 
reduction in heat loss of approximately 30 per cent. 
The Bureau of Standards in Letter Circular 227 on 
Thermal-Insulation states that 1/^ inch of supple- 
mentary insulation is equivalent to an over-all saving 
of from 20 to 30 per cent of fuel. With one inch 
insulation — the building not being weatherstripped 
— the saving is from 30 to 40 per cent of fuel. 



[39] 



Sound Deadening in a Plaster Base 

The same characteristics which make for the re- 
markable thermal-insulating qualities of MAFTEX 
"Thermal-Insulating'* Board and MAFTEX Roof 
Insulating Board, give MAF-LATH, as a plaster 
base, the properties of acting as a deadener of sound 
room-to-room transmission of noises or voices. 



m 



Summary of Advantages 

Summarized, the advantages of MAF-LATH as 
a plaster base are: 

First, the combination in one material of effective 
insulation, structural rigidity, strength and endur- 
ance of bond with gypsum plaster, sound deadening 
and lessened liability of cracking. 




MAF-LATH being installed as plaster base in Philadelphia suburban residence. 



This subject is, however, fully covered in Chapter 
V which precedes. 

Application Cost of MAF-LATH Compared 
with Ordinary Lath 

Competent construction superintendents have 
thoroughly analyzed and compared the cost of labor 
required in applying wood lath with that of MAF- 
LATH and the cost of the finished plaster on each. 

These investigations were made in the field on 
buildings under actual construction, with MAF- 
LATH and wood lath applied in each case in exact 
accordance with recognized practice and plastered 
accordingly. 

The authenticated findings are that the cost of 
the completed gypsum plaster "job" on MAF-LATH 
are only slightly greater than on ordinary wood lath, 
and considerably less than on metal lath. 



Second, the ease and rapidity with which these 
materials may be applied and the plastering finished. 

Third, no increase in first cost and a continual 
saving in fuel costs in winter and increased comfort 
in summer. 




MAF-LATH used throughout as plaster base in 
"Courier-Express" Model Home, Kenmore, N. Y, 



il 



[40] 



MAF-LATH is Exactly Like MAFTEX 

Except in Size 

While MAFTEX will always find favor, and is 
interchangeable as a sheathing, plaster base and 
decorative paneling material, MAF-LATH affords 
an insulating plaster base of more convenient size 
for wall, ceiling and soffit application than the 
larger boards of MAFTEX, and does away with 



MAF-LATH is dimensioned especially for rapid 
and effective application, the 48'' x 16'' size of each 
MAF-LATH covering an area equal to that of nine 
ordinary wood lath. Each dimension, as with MAF- 
TEX, is scant to allow for the %" joint between 
each unit. 

In its 48" length, MAF-LATH adheres to the 
standard of studding spaced on 16" centers; while 





Complete installation of MAF-LATH as plaster base 

in same Philadelphia suburban residence shown on 

opposite page. 



Applying plaster over MAF-LATH. Note ease of 

application, as no forcing is required for "keying" 

of ground coat. 



much of the laying-out, cutting and trimming in its 
application on areas of odd or irregular shape. 

Except for the diflference in size, MAF-LATH is 
exactly like MAFTEX, with all of its insulating, 
structural, sound deadening and other excellent 
qualities. 




MAF-LATH JOINT 

Unretouched photograph of MAF-LATH Joint, illustrating the 

strengthening and stiflFening "T" formed by the plaster. 



the 16" dimension permits a very close approxi- 
mation of the accepted regulation of "breaking of 
joints" of wood lathing at 8 to 9 lath heights. 
The 16" dimension possesses, moreover, the very 
decided further advantage that it permits the MAF- 
LATH to be laid, whenever desired, with its length 
parallel to the studs or joists, the 16" width 
spacing from stud to stud or from joist to joist. 

MAF-LATH like MAFTEX is 7/16" thick, right 
out to the edges which means that it comes to the 
job solid, square and true, undamaged during ship- 
ment and remaining so during handling and appli- 
cation. The ground or scratch coat of plaster pene- 
trates the space at each joint forming a strengthen- 
ing, stiffening, protecting rib against the edges of 
each board. 

MAF-LATH comes wrapped, 15 to the bundle, 
the equivalent of 80 square feet of ordinary lathing. 



[41] 



Directions for the 
Application of MAF-LATH 

Notes as to Framing 

All framing members such as studs, furring strips 
and joists should be set in the usual manner and 
accurately spaced W on centers. Where ceilings 
are to be plastered on the undersides of rafters or 
of collar-beams, the rafters and collar-beams should 
be spaced W on centers. At the tops and bottoms 
of studded walls or partitions where girts, sills and 
plates do not occur, cut in 2'' x 4'' headers between 
the studding to serve as nailing blocks. Not only 
do these blocks serve for nailing the MAF-LATH 
and the metal lath in the angles but they also pro- 
vide "fire-stopping" in the walls and partitions, an 
advantage of great importance in frame construc- 
tion. When the MAF-LATH is to be applied to 
ceilings or rafters, similar headers should be placed 
at the ends of all joists or rafters. This method is 
shown in the drawings on the next pages. Insert 
cross strips between any furring at ends as shown by 
Figure 12. 

Application of the MAF-LATH 

Where ventilating conditions are very good, 
MAF-LATH may be applied without wetting. But 
for the best practice open the bundles of MAF- 
LATH to be used, rwenty-four hours before the 
start of application and sprinkle both sides of each 
MAF-LATH, using about a half-pint of water to 
each side. 

If applied in cold weather, do not allow boards 
to freeze after wetting. 

MAF-LATH should be applied with the ripple 
side exposed and with the long dimension either 
across or parallel to the studs, joists, rafters or fur- 
ring strips. The MAF-LATH should never be 
forced against each other to fit in place. Always 
allow 1/4 inch joint between lath and l^ inch clear- 
ance at ends and stagger the joints at ends. Where 
a tight joint is desirable with other materials — as 
around door frames, window frames and similar 
locations— the MAF-LATH should be brought into 
close contact. 

For nailing MAF-LATH use large-headed lather's 
nails. These should have a 13 gauge shank 1-1/8 
inch long with a 5/16 inch head. Space the nails 4 
inches apart, with nail head driven slightly below 
the surface. 



Reinforcing the Corners and Angles 

Note: The directions which follow are not es- 
sential because of the use of MAF-LATH but are 
given as recommendations because it is commonly 
accepted practice in the case of all lathing applica- 
tions to use an "elastic" material like expanded 
metal as a separate strip or overlap in internal angles 
to prevent any movement in the corners. This dis- 
tributes the strain on the plaster at these places 
caused by the unequal shrinkage of floor structure 
itself and tends to obviate the straight wide-open 
crack in the angles so often seen where this simple 
expedient is not employed. As cracks are also 
almost certain to develop where wood studded 
walls abut masonry (when not furred) the precau- 
tion of spanning over this contact with metal lath 
or wire lath should also be followed as described. 

In all vertical internal angles and in all angles 
between ceilings, soffits and walls lightly attach 
strips of painted expanded metal lath or galvanized 
wire lath cut 8 inches wide and bent into the shape 
of an "L" 4 inches on each side. The strips in all 
cases should be fastened along the edge but not in 
the corner. // corner beads are not specified for all 
vertical corners ^ the same strips of metal lath or wire 
lath should be placed at all such corners. Joints be- 
tween frame and masonry walls which are not furred 
should be reinforced with the same kind of lath, 
lapping 4 inches on the masonry and 4 inches on the 
MAF-LATH. 

Plastering 

MAF-LATH must not be wet after application to 
studding. 

In applying plaster to MAF-LATH it is of course 
essential that the plaster be well troweled and forced 
against the board and then brought to a reasonably 
true plane. Use quick-setting Gypsum Plaster. If 
it does not start to set in one and one-half hours, 
add accelerator or use a different brand of plaster. 

Note: Never use lime plaster or gypsum neat 
plaster containing more than 10% of lime. 

MAF-LATH may be plastered by either the two- 
coat or the three-coat method. 

Two-Coat and Three-Coat Work 

In two-coat work the scratch coat should be about 
1/^'^ in thickness, and the browning coat thoroughly 



[42] 



troweled to form a good bond with the scratch coat 
and giving a combined thickness of %''. In three- 
coat work the scratch coat should be about Yg'' in 
thickness. Before it is hardened it should be well 
scratched or scored. The best results are secured 
by making these scratches parallel and horizontal. 



out showing the under coat, into which it should 
be thoroughly worked. The whole area should be 
gone over as rapidly as possible and brought to a 
true and even plane throughout. 

The circulation of air is important and the rap- 
idity of evaporation of the water will depend largely 




Applying "finish" coat in residence in which MAF-LATH is used as plaster base. 



When the scratch coat is so hard that the pressure 
of the thumb will not break down the edge of the 
scratches, it is ready to receive the brown coat. The 
combined thickness of the scratch and brown coats 
should be %'^ 

In either r^^o or three-coat work the brown coat 
should be rodded to produce a plane surface and 
smoothed with a darby. Any irregularities should 
be taken out with a float and before it is set firm 
and hard the surface should be broomed or rough- 
ened for the finish coat. 

Any type of finish coat may be used but the 
brown coat should be thoroughly dry and hard 
before application. It should then be dampened 
and the finish coat spread as thin as possible with- 



upon the amount of air coming into contact with, 
the plaster. The principal precaution in warm 
weather is to avoid too rapid or uneven drying. In 
cold weather protection of Gypsum Plaster from, 
freezing is only necessary until it is set hard. 

Notes on the Drawings 
for MAF-LATH Application 

The drawings on the following pages have beea 
prepared especially to illustrate the points men- 
tioned in the "Directions" on the preceding page. 

In Figure Ten the application of MAF-LATH to- 
a stud wall is clearly shown. In this drawing it 
will be noted that a header is placed between the 



[43] 



studs with the bottom of the header at a level with 
the top of the rough floor. The MAF-LATH should 
not rest on the rough floor or on the MAFTEX Roof 
Insulating Board which is placed thereon as a sound 
deadener. 

The directions specify the sizes of the nails to be 
used as well as the spacing. 




Fig. 10. MAF^LATH applied as plaster base, and MAFTEX 
applied as sheathing and sound deadening in frame construction. 

This drawing also shows MAFTEX Structural In- 
sulating Board applied to the outside of the studs 
as sheathing. The directions for application of 
MAFTEX for this purpose are given fully in Chap- 
ter III of this Manual. The MAFTEX ROOF 
INSULATING BOARD used as sound deadener 
between the rough and finished floor, as shown in 
Figure Ten, also serves another purpose as well, for 



it provides insulation against drafts which may come 
through the floor and which are especially annoying 
and dangerous if the floor happens to be over an 
open porch or the unheated portion of a cellar or 
basement. 

Figure Eleven illustrates the method of applying 
MAF-LATH to a wood framed building at the 
ceiling joists. In this case the girt, which is let 
into the studs, forms the nailing base for the top 
edge of the MAF-LATH and the metal lath in the 
ceiling angle. Other than this the directions pre- 
viously given apply here. On the ceiling it will be 
seen that headers are let in between the joists to 
provide a nailing for the edge of the ceiling MAF- 
LATH and the metal lath. 

This drawing also shows the installation of the 
metal lath at the angles of the side walls and the 
ceiling. Similar strips of lath should be run up and 
down in all internal angles and external angles un- 
less corner beads be used. 




Fig. 11. MAF-LATH applied as a plaster base on ceiling and 
side wall construction. 



144} 



Figure Twelve shows MAF-LATH applied to the 
inside of a brick wall on furring strips. All of the 
directions previously given are equally applicable 
here. The most important part of this detail is the 
header between the furring strips which provides a 
base for the nailing of the bottom of the lowest 
MAF-LATH and the sub-base providing at the same 
time a fire, draft and vermin stop. Similar strips 
should be inserted at the heads of the vertical strips 
beneath the ceiling joists to take care of the nailing of 
the edge of the MAF-LATH and the metal lath angle 
strip. Strips of similar metal lath should be placed 
at all joints between masonry and wood stud or 
joist construction. This applies particularly to par- 
titions and wood framing around chimney breasts 
or fireplaces. 




Fig. 12. MAF-LATH applied to furring strips on the interior 
of a masonry wall. 



MAFTEX as a Plaster Base 
(Directions for Application) 

Notes on Framing 

All framing members and headers should be set 
in the manner described under the directions for 
the application of MAF-LATH. Wherever joints 
occur between sheets of MAFTEX on studded walls, 
cut in T^ X 4'' headers between the studding to 
serve as nailing blocks for the ends of the MAF- 
TEX. When the MAFTEX is to be applied to 
ceilings or rafters, similar headers should be placed 
at the ends of all MAFTEX sheets. 

Application of the MAFTEX 

It is important that the entire surface of each 
board be thoroughly wet 24 hours before applica- 
tion, using not less than one quart of water for 
each side of every 4x8 feet of board. 

This dampening should be done in an even man- 
ner and care should be taken that the boards do 
not freeze in cold weather. Dampen only as many 
boards as can be used in one day and do not allow 
the boards to dry out completely before applying. 

MAFTEX on studding should be applied with 
the ripple side exposed and with the long dimension 
parallel to the framing. It should have a solid 
bearing under all edges. The boards should never 
be forced against each other to fit in place. Always 
allow 14 i^ch clearance between boards at both ends 
and sides. Where a tight joint is desirable with 
other materials — as around door frames, window 
frames and similar locations the MAFTEX should 
be brought into close contact. 

For nailing MAFTEX use large-headed galvan- 
ized "roofing" nails ll/^ inch in length. Beginning 
at the top or one end drive nails down the inter- 
mediate studs, joists, rafters or furring strips, 
spacing the nails 6 inches apart. It is important 
that the nailing always be done on the inside of the 
board before the edges. Follow by nailing the top 
edge, bottom edge and last of all the side edges. 
Along all edges the nails should be placed 4 inches 
apart and 3/8 inch from the edge. The nails 
should be driven until the head is slightly below the 
surface of the board. 



[45] 



Alternate: The above provisions are especially 
applicable when the work is done by carpenters. If 
the MAFTEX is applied by lathers the sheets may be 
nailed with special lather's blued nails 11/^" long 
with ^y round heads and 13 gauge shanks, or with 
1^" blued asbestos shingle nails with Jf" round 
heads and lll^ g^^uge shanks, provided all such nails 
are spaced not more than 4" apart throughout. 

Reinforcing the Joints and Corners 

Over all joints lightly attach a strip of 4" wide 
painted expanded metal lath or galvanized wire lath. 
Before applying the lath be sure that all joints are 14 
inch wide. If not, cut open with knife, chisel or 
saw. In all vertical internal angles and in all angles 



between ceilings, soffits and walls lightly attach 
strips of similar lath cut 8'' wide and bent into the 
shape of an "L" 4'' on each side. The strips in all 
cases should be fastened along the edge but not in 
the corner. If corner beads are not specified for 
all vertical corners, similar strips of metal lath or 
wire lath should be placed at all such corners. 
Joints between frame and masonry walls which are 
not furred should be reinforced in the same manner. 

Plastering 

Apply quick-setting GYPSUM PLASTER directly 
to the MAFTEX following the directions given for 
plastering on MAP- LATH. 





MAFTEX used as plaster base in "Income Home,' 
Kenmore, N. Y. 



MAFTEX used as plaster base in Duplex Apartment, Scranton, Pa. 
Schneider Bros., Scranton, Pa., builders. 



Eiy I 






MAF-LATH used as plaster base throughout home in Egg 
Harbor, N. J. 



MAFTEX used as plaster base throughout residence in Rye, N. Y. 
H. S, Stevens Co., Inc., Rye, N. Y., builders. 



[46] 



General Notes on Plastering 



TO secure the most satisfactory results when 
plastering on MAFTEX it is important that 
only gypsum plaster be used and for this reason 
the following data regarding such plasters are pre- 
sented as of interest to the architect. 

Gypusm base coat plasters are manufactured both 
neat (without sand) and sanded (with sand) and 



tain changes be made in these specifications which 
would tend to raise the quality of the products. The 
quotations which follow contain these tentative 
revisions. 

L Gypsum Neat Plaster 

6. Gypsum neat plaster is a plastering material in which 
not less than 60.5 percent of the cementitious material is 




each kind is ordinarily marketed in paper bags 
(weighing 80 pounds) and in jute bags (weighing 
100 pounds). Either of these will be furnished un- 
fibered, hair fibered or wood fibered. The most com- 
mon, and the one which should be used for base coat 
work on MAF-LATH and MAFTEX, is the hair 
fibered type. 

The American Society for Testing Materials in 
1921 adopted Standard Specifications for Gypsum 
Plasters. At the meeting of the Society in 1926, 
Committee C-11 on Gypsum recommended that cer- 



MAFTEX used as plaster base in residence near Merchantville, N. J. 
Edwards & Green, Camden, N. J., architects. 

calcined gypsum, calculated from the SOg 
mixed at the mill with other materials. 



content and 



7. Gypsum neat plaster shall contain not less than 60.5 
percent, by weight, of calcined gypsum, calculated from the 
SO3 content. The remainder may consist of materials to 
control the working quality, setting time and fibering. 

8. Gypsum neat plaster when mixed with 3 parts, by 
w^eight, of testing sand shall set in not less than 8 hours 
nor more than 32 hours. ' 

9. Gypsum neat plaster shall have a tensile strength of 
not less than 150 lbs. per square inch (lOl/^ kg. per 
sq. cm.) . 



[47] 



For certain localities where the sand is poor, for 
cold weather use to avoid trouble with frosty sand, or 
where it is not practicable to mix the sand on the 
job, gypsum plaster is supplied mixed with sand. 
Only clean sharp, siliceous sand, free from impuri- 
ties, is used. As the sand is present in the correct 
proportions, no further sand should be added. 

The Standard Specification for Gypsum Ready- 
Sanded Plasters of the American Society for Testing 
Materials as tentatively revised is as follows: 

2. Gypsum ready-sanded plaster is a plastering material 
in which the predominating cementitious material is calcined 
gypsum, and which is mixed at the mill with all the con- 
stituent parts, including sand, in their proper proportion. 
It requires only the addition of water to make it ready for 
use. 

11. Gypsum Ready-Sanded Plaster 

3. Thee following shall govern the composition of 
gypsum ready-sanded plaster for the desired coats. 

(a) Scratch or First Coat. Gypsum ready-sanded plaster 
used for scratch or first coat shall contain not more than 
t\^'0-thirds, by weight, of sand. The other one-third shall 
contain not less than 60.5 per cent, by weight, of calcined 
gypsum calculated from the SO3 content. The remainder 
may consist of materials to control the working quality, 
setting time, and the fibering. 

(b) Browning or Second Coat. Gypsum ready-sanded 
plaster used for browning or second coat shall contain not 
more than 75 per cent, by weight, of sand. The remainder 
shall contain not less than 60.5 per cent, by weight, of 
calcined gypsum, calculated from the SO3 content. The 
other 39.5 per cent of this remainder may consist of mate- 
rials to control the working quality, setting time, and the 
fibering. 

4. The time of set of gypsum ready-sanded plaster shall 
be as follows: 

(a) Scratch or First Coat. This plaster shall set in not 
less than 11/^ nor more than 7 hours. 

(b) Browning or Second Coat. This plaster shall set in 
not less than 2 nor more than 6 hours. 




MAFTEX used as subsheathing and plaster base in 

Heliport, L. I., home. 

Armstrong & Pierman, Bellport, L. I., contractors. 



5. The tensile strength of gypsum ready-sanded plaster 
shall be as follows: 

(a) Scratch or First Coat. This plaster shall have a 
tensile strength of not less than 75 lbs. per square inch 
(514 kg. per sq. cm.). 

(b) Brotvning or Second Coat. This plaster shall have 
a tensile strength of not less than 50 lbs. per square inch 
(3V2 kg- P^^ ^4- ^"^•)' 

Application 

Regarding two-coat work: Circular No. 151 of the 
Bureau of Standards entitled '^Wall Plaster, Its 
Ingredients, Preparation and Properties," states in 
part: 

'' 'Doubled-up/ laid-off/ or 'laid-on' work, as it is 
variously called in different localities, means the 
application of the scratch and brown coats together, 
or at least without permitting the usual time to 
elapse between them. The scratch coat is applied 
in the way specified above, but it is not permitted to 
harden, nor is its surface scratched. The application 
of the brown coat is started immediately after finish- 
ing the application of the scratch coat. This method 
is obviously cheaper than straight three-coat work, 
but certain precautions are essential to its successful 
use. The brown coat must be applied before the 
hardening of the scratch coat has progressed far 
enough to produce a glazed surface. The backing 
must be sufficiently rigid of itself that it will not 
yield under the pressure of the trowel, and will not 
sag under the weight of the combined coats. If it 
deflects to any appreciable extent, the keys which 
hold the scratch coat to it will probably be broken, 
and if it sags, it will be found extremely difficult to 
bring the brown coat out to a true plane surface. 
For these reasons, doubled-up work shall not be ap- 
plied to metal lath. Its use on wood lath is not 
recommended, particularly if the plaster is to be 
seven-eighths inch thick. On masonry backings the 
use of doubled-up work is largely a question of ap- 
plication — if the plasterer succeeds in making the 
plaster stick and is able to form a true and plane sur- 
face the work will be satisfactory. This depends on 
the thickness of the plaster and the nature of the 
backing. It is difficult to apply a doubled-up coat of 
a thickness greater than five-eighths inch. The great 
suction exerted by gypsum tile makes the application 



[48] 



of doubled-up work easy; on day tile it is almost 
impossible." 

Proportions 

It will be noted that no mention is made in the 
Directions of the proportions for the mix of plaster. 
This has been omitted purposely as the instructions 
of the manufacturer of the piaster should be fol- 
lowed. 



Gypsum plaster is usually properly retarded by the 
manufacturer but under certain conditions it will be 
found that the use of impure water will cause the 
plaster to set faster or slower than it should for the 
best results. When the plaster sets too slowly it can 
be accelerated by use of the manufacturer's **Acceler- 
ator." When this material is not at hand, the plaster 
on the sides and bottom of the mixing box may be 
scraped off and mixed with the fresh plaster. An- 




C. H. Eggleton 

Boston, Mass. 

Architect. 



MAFTEX used as plaster base and sound deadener 
in fine residence, Lexington, Mass. 



Wilson & Tomlinson, 
Boston, Mass. 
Contractors, 



Ordinarily proportions for the First or Scratch 
coat should be made the same as those for wood lath, 
namely; one part plaster, hair fibered, to not more 
than two parts, by weight, of dry sand. The Second 
or Browning coat should usually be one part plaster, 
unfibered, to not more than two parts, by weight, of 
dry sand. The second coat should be applied with 
strong pressure and straightened to a true, even 
plane and the surface broomed or otherwise rough- 
ened to receive the finishing coat. The second coat 
should be applied when the first coat is set firm and 
hard but before it is dry. The selection of the type 
of finishing coat will depend upon the effect desired 
but the finishing coat should not be applied until the 
base plaster is set firm and hard and thoroughly dry. 
The surface of the base coat should be sprinkled 
with water before the finish coat is applied. 



other remedy is the soaking of crushed pieces of 
set-up plaster for two hours in a barrel of water and 
using this water in the mix. If this does not acceler- 
ate the time enough dissolve from 4 to 6 pounds of 
alum or commercial zinc sulphate in a barrel of 
water. Depending upon the speed of set-up desired, 
mix from 2 to 12 quarts of this solution in the water 
required for the mixing of one bag of plaster. 

Plasters may be retarded by using the manufactur- 
er's *'Retarder.'* If this cannot be obtained readily 
dissolve one pound of pulverized glue in one gallon 
of hot water and use about one pint of this solution 
in the water necessary for the mixing of one bag of 
plaster. 

Valuable suggestions regarding the use of gypsum 
plaster may be secured from the Gypsum Industries, 
844 Rush Street, Chicago, Illinois. 



[49] 





Steel deck roof under construction. 



Two layers of MAFTEX being applied over steel deck. 





Roofing felt being applied over MAFTEX. 



Finished slag roof. 




CAMDEN COUNTY VOCATIONAL SCHOOL, CAMDEN, N. J. 



Lackey & Hettel, Inc. 

Architects 

Camden, N. J. 

MAFTEX ROOF INSULATING BOARD used for entire roof insulation. Illustrations show successive 



Geo, Bach MANN 

Contractor and Builder 

Camden, N. J. 



Stages of this typical installation. 
[50] 



CHAPTER VII 



Roof Insulating Board 

on various types of flat roof decks tinder built-up roofing 

NOTE 

The "Directions'' which jollow are intended jor Flat Roojs not exceeding a slope oj 
3 inches to the foot if asphalt is used and 2 inches to the foot if coal tar pitch is used. W^hen 
the application is to be on slopes in excess of the above suitable provision for fastening the 
felts must be made and it is recommended that the suggestions and specifications of the manu- 
facturers of built-up roofing materials be followed. 



EVERY roof, whether it be sloping or flat, needs 
insulation. The greatest loss of heat in winter 
and the greatest in-leakage of heat in sum- 
mer is through the roof of any structure — a point 
which may be readily appreciated by comparing the 
temperature in any attic or loft space in either sum- 
mer or winter with the temperature in the rooms 
below. 

The roofs of the majority of large buildings such 
as factories, schools, hotels, offices, apartment houses 
and public buildings are of what is known as "flat 
roof construction." These roofs usually have enough 
slope to shed water into the gutter but they are still 
called flat roofs. 

Purposes of Roof Insulation 

Insulation is principally used on flat roofs for 
either or both of two purposes; first, to conserve 
heat; second, to prevent condensation. It is also used 
to keep out heat in summer, although the value 
of insulation for this purpose is not as widely ap- 
preciated on flat roofs of other buildings as it is 
for residences. 

Another and very important use of insulating 
board on flat roofs of the concrete type is for the 
prevention of the expansion and contraction which 
inevitably takes place and which often does con- 
siderable damage to the roof covering. 

The flat roof deck may be constructed of a wide 
variety of materials. In factories and non-fireproof 
buildings of all types, probably the most common is 
the wood deck. Depending upon the span, weight 



of the roof covering and other factors, the thickness 
of the deck will vary from one inch to three inches. 
On top of this may be placed the usual standard 
roof covering or some type of metal roofing. For 
fire-resistive construction the deck may be of steel 
with gypsum slabs, concrete beams and tile slabs, 
solid reinforced concrete slabs, concrete and cinder 
fill or precast concrete or gypsum tile. The thickness 
of the types will also vary with other factors. In 
some structures a metal roof deck is used under the 
usual roof coverings, a type which is steadily in- 
creasing in popularity. 

Heat Savings 

Although insulation of one type or another may be 
applied to flat roofs for all of the reasons outlined 
above, the primary purpose is usually to retain heat 
inside the structure. Every insulating material has 
a definite factor of heat conductivity which is a 
measure of its insulating value, and is commonly 
expressed in British thermal units. In order to have 
a definite basis for evaluating this factor, and espe- 
cially for the purpose of standardizing test methods, 
the conductivity is limited to a definite area — one 
square foot; a definite time — one hour; a definite dif- 
ference in temperature — one degree; and a definite 
thickness — one inch. 

Resistance Factor 

For insulating materials a resistance factor is 
sometimes used instead of the conductivity factor. 
This resistance factor is the reciprocal of the conduc- 
tivity as expressed above. In this connection it 



[51] 



should be remembered that the higher the resistance 
the better the material from an insulation stand- 
point, but that when conductivity is considered the 
lower the factor the better the insulation. 

The coefficient of conductivity of 0.34 for MAF- 
TEX may be used with safety in all computations of 
thermal insulation. 

For purposes of comparison it is interesting to 
note that the conductivity of concrete is from 6 to 
9 British thermal units per inch, per hour, per square 
foot, per degree Fahrenheit difference in tempera- 
ture. In other words plain concrete allows from 
seventeen to twenty-five times as much heat to pass 
through it in the same time as does MAFTEX. See 
Chapter I for conductivity of various materials. 

With these figures as a basis it is not only possible 
but thoroughly practical to figure the fuel savings 
which can be obtained by applying one or more 
layers of MAFTEX on top of the roof deck, whether 
this be built of wood, metal, concrete or other 
materials. Furthermore the amount of radiation 



which can be saved can also be readily computed. 
A table showing the coefficients of Heat Trans- 
mission for various types of roofs in terms of British 
thermal-units per hour, per square foot, per degree 
Fahrenheit difference in temperature is given below. 
In using this table the architect or engineer 
should first determine upon the type of roof deck to 
be used on the structure and from the table ascertain 
the coefficient of transmission for the roof unin- 
sulated and for the roof insulated with the number 
of layers under consideration. For example, a 4'^ 
concrete roof without insulation has a coefficient of 
0.60, whereas with two layers of MAFTEX applied, 
the coefficient is 0.23 or a difference of 0.37 (0.60 — 
0.23^0.37). This means that the two layers of 
MAFTEX will keep in that amount of heat in 
terms of British thermal units. The architect should 
next determine from the weather reports of his 
locality the average outside temperature during the 
heating season. Assume this to be 34 degrees 
Fahrenlieit. The temperature of air on the under- 
side of the roof should then be determined according 



Coefficients of Heat Transmission of Various Types of Roofs 

with MAFTEX Roof Insulation 





Uninsulated 


With 

One Layer 

Maftei 


With 

Two Layers 

Maftex 


With 

Three Layers 

Maftex 


With 

Four Layers 

Maftex 


Witli 

Five Layers 

Maftex 


TYPE OF ROOF 



0| 


IJ 

6^ 




% 


g 








Is 


.11 


c 


•li 

(LI 0) 

6? 


c 



c 


Steel Deck 


0.84 
0.70 
0.65 
0.60 
0.52 
0.47 
0.49 
0.35 
0.27 
0.22 
0.50 
0.47 
0.44 
0.40 
0.37 
0.42 
0.33 
0.27 
0.23 
0.38 
0.30 
0.25 
0.22 
0.48 
0.40 
0.33 
0.28 
0.25 
































0.39 
0.36 
0.35 
0.33 
0.31 
0.29 
0.30 
0.24 
0.20 
0.17 
0.30 
0.29 
0.28 
0.26 
0.25 
0.27 
0-23 
0.20 
0.18 
0.25 
0.22 
0.19 
0.17 
0.29 
0.26 
0.23 
0.21 
0.19 


53. 
49. 
47. 
45. 
41. 
39. 
40. 
32. 
27. 
23. 
40. 
39. 
37. 
35. 
33. 
36. 
31. 
27. 
24. 
34. 
29. 
25. 
23. 
39. 
35. 
31. 
28. 
25. 


0.26 
0.24 
0.24 
0.23 
0.22 
0.21 
0.21 
0.18 
0.16 
0.14 
0.21 
0.21 
0.20 
0.19 
0.18 
0.20 
0.17 
0.16 
0.14 
0.19 
0.17 
0.15 
0.14 
0.21 
0.19 
0.17 
0.16 
0.15 


69. 
66. 
64. 
62. 
59. 
56. 
57. 
49. 
42. 
37. 
57. 
56. 
55. 
52. 
50. 
53. 
47. 
42. 
38. 
51. 
45. 
41. 
37. 
56. 
52. 
48. 
44. 
40. 


0.19 
0.18 
0.18 
0.17 
0.17 
0.16 
0.16 
0.14 
0.13 
0.12 
0.17 
0.16 
0.16 
0.15 
0.15 
0.16 
0.14 
0.13 
0.12 
0.15 
0.14 
0.13 
0.12 
0.16 
0.15 
0.14 
0.13 
0.12 


77. 
74. 
72. 
71. 
68. 
65. 
67. 
59. 
52. 
47. 
67. 
66. 
64. 
62. 
60. 
63. 
57. 
52. 
49. 
61. 
55. 
51. 
47. 
66. 
62. 
57. 
53. 
50. 


0.15 
0.15 

0.14 
0.14 
0.14 
0.13 
0.14 
0.12 
0.11 
0.10 
0.14 
0.13 
0.13 
0.13 
0.12 
0.13 
0.12 
0.11 
0.10 
0.13 
0.12 

o.u 

0.10 
0.13 
0.13 
0.12 
O.U 
0.11 


82. 
79. 
78. 
76. 
74. 
71. 
73. 
65. 
59. 
54. 
73. 
72. 
71. 
68. 
66. 
69. 
64. 
59. 
55. 
67. 
62. 
58. 
54. 
72. 
68. 
64. 
60. 
57. 


0.13 
0.12 
0.12 
0.12 
0.12 
0.11 
O.U 
0.10 
0.10 
0.09 
O.U 
O.U 
O.U 
O.U 
O.U 
O.U 
0.10 
0.10 
0.09 
O.U 
0.10 
0.09 
0.09 
O.U 
O.U 
0.10 
0.10 
0.09 


85. 


2" Stone Concrete 


83. 


3" " " 


81. 


4// a a 


80. 


6" " " . 


78. 


8" " " ; 


76. 


2" Cinder Concrete 


77. 


4// a u 


70. 


6" " " 


65. 


Q// CI {( 


60. 


2" Stone Concrete with Cinder Fill 


77. 


0// (( (I a u li 


76. 


Atr u u a u (( 


75. 


f^ff (( « (I i( « 


73. 


QAA a ii a u u 


71. 


2" Concrete 2" Hollow Tile 


74. 


cy/f ({ Af/ (I (I 


69. 


2" " 6" " " 


64. 


2" 8" " " 


61. 


Aff H (J// 11 (I 


72. 


^ff 11 ^ff a t( 


67. 


^// H Q// H 11 


63. 


Af/ a Q/f « « 


60. 


1" Wood Plank (Vs") 


76. 


lU" « « (IW) 


73. 


2" " " (1^") 


69. 


2J^" " " (2M'0 


66. 


3" " " (2M-") . 


62. 






Cnftffip.iftiits PixnrfiSRp.fi in R.t.n. drf sn. 


ft. ner 


Decree 


Fahrei 


iheit p( 


ir Hour 


. All c 


oefficien 


its inch 


ide roof 


in^. C 


oefficien 


its 



will not apply for excessive wind velocities. 



[52] 



to the nature of the work or occupancy in the upper 
story. Assume it to be 75° Fahrenheit. The differ- 
ence in temperature inside and outside is then 41° 
Fahrenheit (75°— 34°=4l°) . 

The length of the heating season may be de- 
termined for the iocahty but we can consider 210 
days or 5040 hours in this problem. We are now 
ready to-proceed. The saving is 0.37 British thermal 
units; this multiplied by the number of degrees dif- 
ference in temperature (41° F,) and the result by 
the number of hours will give the number of British 
thermal units saved by two layers of insulation. 
Assume that the roof contains 15,000 square feet. 

0.37 B.t.u. saving per degree difference in cemperature 
per hour per square foot X 41 degrees difference 
in temperature = 15.17 B.t.u. per square foot per 
hour. 

15.17 B.t.u. per scpare foot per hour X 5040 hours 
= 76,457 B.t.u. per square foot during heating 
season. 

76,457 B.t.u. per square foot during heating sea- 
son X 15,000 square feet = 1,146,852,000 B.t.u. 
total. 

The ordinary coal may be considered as having 12,000 
B.t.u. per pound, about 50% of which is useful, or 6,000 
B.t.u. 

Dividing — 1,146,852,000 B.t.u. from above -f- 6,000 
B.t.u. per lb. = 191,142 lbs. or in Tons 191,142 
lbs. -f- 2,000 lbs. = 95.6 Tons. 

Coal saving per year for a roof area of 15,000 sq. ft. 

From the foregoing it will be seen that it is a 
simple matter to figure the savings in the amount 
of fuel. The dollar value can then readily be 
measured at the prevailing local price for the grade 
of coal to be burned. 

Condensation Eliminated 

When warm moist air comes in contact with a 
cool surface, condensation results. Considered in 
connection with roofs and side walls of manufactur- 
ing plants and other structures, this problem of con- 
densation may become very serious. 

Warm air will hold more moisture than cold air. 
The inside surfaces of a building (i.e., roofs and 
side walls) are continually cooled in winter by the 
cold air in contact with the outside of the structure. 
Thus there exists an ideal situation for the formation 
of condensation when the warm air, usually quite 
moist, comes against the cooled inside surface of 
roof or wall. "Sweat" is formed and sometimes is 
so serious as to drip on men, machinery or products 
below. 



The problem, then, is one of keeping the inside 
surface of the building at as nearly the temperature 
of the inside air as possible. The logical answer is 
to insulate the walls and the roof to prevent the 
loss of heat and the consequent cooling of the 
interior surface. 

The amount of insulation required to prevent con- 
densation involves questions of temperatures, roof 
construction, ventilation, humidities and other fac- 
tors. When the problem becomes complex, a com- 
petent heating and ventilating engineer should be 
consulted. 

For ordinary conditions, however, it is perfectly 
feasible to determine the number of layers of MAF- 
TEX required to prevent condensation and with this 
thought in mind, the chart on Page 54 has been 
prepared. 

Other Purposes of Roof Insulation 

In addition to the conservation of heat and pre- 
vention of condensation, roof insulation is of great 
value in keeping out the heat of the sun in summer. 
One great noticeable fault with one story factories, 
especially, and with the top floor of other structures 
has always been the "close feeling" and the heating 
up caused by the direct rays of the summer sun beat- 
ing upon the unprotected roof. 

Naturally the same material which keeps heat 
inside the building in winter will keep heat outside 
the building in summer and by the addition of 
insulation the top story can be made comfortable in 
the hottest weather. The insulation prevents the 
heat of the sun from reaching the still air close to 
the roof and raising its temperature to an unbearable 
degree. The transmission may be reduced as much 
as 30% with one layer of MAFTEX on a 2-inch 
wood roof deck. 

Expansion and Contraction Reduced 

Another valuable feature of insulation on a con- 
crete deck is the reduction in expansion and contrac- 
tion. The expansion of a concrete roof deck may be 
materially reduced, sometimes as much as 50 to 60 
percent by adding two layers of MAFTEX to the 
concrete beneath the roof covering. 

Directions and drawings for the application of 
MAFTEX on various types of roof decks are printed 
on the succeeding pages. 



[53] 



Condensation Chart 

The chart below has been prepared to assist the architect and engineer in determining the number of 
hiyers of MAFTEX required to prevent condensation under ordinary conditions. The data used as the basis 
of this chart are a constant inside temperature at the roof line of 100° F. and an outside temperature of 0" 
F. When these conditions obtain in the proposed structure this chart may be used. If other inside tempera- 
tures are to be considered, the specially prepared chart on Page 63 should be consulted. ^ 



So 6o 70 



Bo 



So 




So 



[54] 



Directions and Specifications for Application 

Concrete Roof Decks 



Concrete Deck 

The concrete roof deck should be well seasoned 
and absolutely dry before proceeding with any roof- 
ing work. The surface should present an even plane 
and should be thoroughly cleaned of loose materials 
and dirt. The deck should be examined by the roof- 
ing contractor and be in such condition as to be 
acceptable to him as well as the architect. 

Note: Under certain conditions of smoothness or absorp- 
tion and with some types of concrete it will be desirable to 
fise a waterproof primer to facilitate a proper bond. 

Note: Under the specification for Concrete W^ork, refer- 
ence should be made to the fact that the contractor shonld 
leave the roof deck properly graded to drains, scuppers or 
other outlets and of even plane throughout, free from 
depressions or bumps. 

Application of MAFTEX 

The slab should be well mopped with hot asphalt 
or pitch and the MAFTEX Roof Insulating Board 
imbedded thoroughly by pressing the entire surface 
to the deck. A space of l/g inch should be kept be- 
tween all edges of the Boards and the edges be well 
filled with asphalt or pitch. 

If more than one layer of MAFTEX is to be used 
mop uniformly and completely the top surface of 
each layer. The joints should be staggered and the 
boards imbedded in the hot asphalt. 

MAFTEX should be neatly cut to fit around pro- 
jections such as vent pipes, flag poles, etc., and at 
penthouses, walls, skylights, etc. 

Do not lay more MAFTEX than can be covered 
with roof covering in one day. Protect exposed 
edges of MAFTEX when work is stopped, by a sheet 
of roofing paper weighted to hold it in place. This 



CONCRETL 
DLCK 




MAFTEX on Concrete Roof Deck 

is necessary for, although the MAFTEX is not in- 
jured by water, no bituminous material will bond 
satisfactorily on a wet surface or a surface moistened 
by night air. 

If the MAFTEX is to be installed on sloping 
roofs where there may be possibility of slipping, the 
sheets should be anchored. 

Any "standard" built-up roofing may be applied to 
the MAFTEX following the directions of the manu- 
facturer. 

Architects' Short Form Specification 

(For Inclusion in Roofing Contractors* Work) 

The contractor for roofing shall furnish and 
apply . . . layers of MAFTEX Roof Insulating 
Board to the concrete deck before installing roofing, 
MAFTEX shall be applied in accordance with the 
directions of the maker published on Page 55 of the 
MAFTEX Manual, dated 1928, and on file in the 
office of the architect. 

See also ''Note'' under ''Concrete Deck.'* 



[55] 



Wood Roof Deck 

(When Condensation is not a Factor) 



Wood Deck 

All loose boards should be securely fastened and 
any raised edges or sharp corners adzed smooth. 
The wood roof deck should be thoroughly cleaned 
of all loose materials and dirt. 

Application of MAFTEX 

Apply MAFTEX Insulating Board to the entire 
surface of the roof, allowing Yg'' clearance between 
all edges. Nail the center of the sheets at random 
to secure them in place and nail all edges 12'' on 
centers. Large head 11/^'' roofing nails should be 
used and all nails should be driven home. 

If more than one layer of MAFTEX is to be used, 
apply succeeding layers direcdy over the first layer, 
taking care that all joints are well staggered. Only 
the final layer need be nailed through to the wood 
roof deck and nails proportionately longer should 
be used. 

MAFTEX should be neatly cut to fit around pro- 
jections such as vent pipes, flag poles, etc., and at 
penthouses, walls, skylights, etc. 

Any ^'standard" built-up roofing may be applied 
to the MAFTEX. If there is any possibility of the 
pitch or asphalt dripping through the wood roof 
deck, the wood deck should be covered with a sheet 
of rosin-sized paper or saturated felt before the 
MAFTEX is laid. 




MAFTEX on Wood Roof Deck 
(When Condensation is not a Factor) 

Do not lay more MAFTEX than can be covered 
with roof covering in one day. Protect exposed 
edges of MAFTEX when work is stopped by a 
sheet of roofing paper weighted to hold it in place. 

Architects' Short Form Specification 

(For Inclusion in Roofing Contractors' Work) 

The contractor for roofing shall furnish and apply 

layers of MAFTEX Roof Insulating Board to 

the wood deck before installing roofing. MAFTEX 
shall be applied in accordance with the directions of 
the maker, published on Page 56 of the MAFTEX 
Manual, dated 1928, and on file in the ofiice of the 
architect. 



Wood Roof Deck 

[When Subject to High Humidities) 



Wood Deck 

All loose boards should be securely fastened and 
any raised edges or sharp corners adzed smooth. 
The wood roof deck should be thoroughly cleaned 
of all loose materials and dirt. 

Water-Proof Paper 

The entire roof area should be covered with a 
coated water-proof paper weighing not less than 
7 pounds per square, lapped 6 inches and cut to 



form water-proof joints at wall angles. Nail sheet 
under lap enough to hold in place. If necessary, the 
bottom of each sheet may be nailed with galvanized 
nails and tin caps 20'' on centers. 

Apply MAFTEX Roof Insulating Board over this 
water-proof course, allowing y^'' clearance between 
all edges. Nail the centers of the sheets at random 
to secure them in place and nail all edges 12 
centers. Use large head 11^'' roofing nails. 



on 



[56] 



When more than one layer of MAFTEX is to be 
used, apply succeeding layers directly over the first 
layer taking care that all joints are staggered. Only 
the final layer need be nailed through the deck, 
using nails proportionately longer. 

MAFTEX should be neatly cut to fit around pro- 
jections such as vent pipes, flag poles, etc., and at 
penthouses, walls, skylights, etc. Any "standard" 
built-up roofing may be applied to the MAFTEX. 

Note: Under certain condttwns H may he necessary to 
increase the amount of waterproofing by mopping nm\ormly 
over the water proa] paper and each succeeding layer oj 
MAFTEX as shown in the drawing. The MAFTEX should 
be firmly imbedded in the fnopping. The nailing shown 
may not be necessary on flat roofs when mopping is used 
but should be required wherever there is possibility of 
slipping, 

(For more severe conditions, consult MacAndrews 
& Forbes Company.) 

Architects' Short Form Specification 

(For Inclusion in Roofing Contractorft' Work) 

The contractor for roofing shall furnish and apply 
. . . .layers of MAFTEX Roof Insulating Board over 




MAFTEX on Wood Roof Deck 

(When Subject to High Humidifies) 

a waterproofing course of (here insert kind desired) 
on the v/ood deck before installing roofing. Water- 
proofing course and MAFTEX shall be applied in 
accordance with the directions of the maker pub- 
lished on Pages 56 and 57 of the MAFTEX Manual, 
dated 1928, and on file in the office of the architect. 

Note: The above does not iyiclude mopping or nailing. 
If conditions require, these should be inserted in the ''Short 
FormJ' 



Unit Tile Deck 



Unit Tile Deck 

All joints should be carefully pointed and the en- 
tire roof deck thoroughly cleansed of loose materials 
and dirt. The deck should be examined by the 
roofing contractor and be in such condition as to be 
acceptable to him. 

Application of MAFTEX 

Note: Under certain conditions of smoothness or absorp- 
tion and with certain types of tile, it will be desirable to use 
a waterproof primer to facilitate a proper bond. 

Spot mop or strip mop tile units. Mopping should 
be kept back at least four inches from joints of the 
tiles. 

Note: // coal tar pitch is used or if there is any possi- 
bility of dripping through the joints a ''Dry Sheet" of 
coated paper, lapped 6 inches should be laid over the 
entire surface. 



While the mopping is hot, imbed the MAFTEX 
thoroughly by pressing the entire surface to the deck. 
A space of Y^'' should be kept between all edges 
and the edges be well coated. 

If more than one layer of MAFTEX is to be used, 
mop uniformly and completely the top surface of 
each layer. The joints should be well staggered and 
the boards thoroughly imbedded. 

MAFTEX should be neady cut to fit around pro- 
jections such as vent pipes, flag poles, etc., and at 
penthouses, walls, skylights, etc. 

Do not lay more MAFTEX than can be covered 
with roof covering in one day. Protect exposed 
edges of MAFTEX, when work is stopped, by a 
sheet of roofing paper weighted to hold it in place. 

If waterproofing is not required, the MAFTEX 
Roof Insulating Board may be installed as described 
for wood deck roofs and the moppings omitted. 



[57] 



If the MAFTEX is to be installed on sloping roofs 
where there may be possibility of slipping, the sheets 
should be nailed or otherwise anchored. 

Any "standard" built-up roofing may be applied 
to the MAFTEX. 

Architects' Short Form Specification 

(For Inclusion in Roofing Contractors' Work) 

The contractor for roofing shall furnish and apply 

layers of MAFTEX Roof Insulating Board to 

the unit tile deck before installing roofing. MAFTEX 
shall be applied in accordance with the directions 
of the maker published on Page 57 of the MAFTEX 
Manual, dated 1928, and on file in the office of the 
architect. 




MAFTEX on Unit Tile Deck 



Metal Roof Deck 



Metal Roof Deck 

The metal roof deck should be properly installed 
in accordance with the directions of the manufac- 
turer of the metal deck. It should be left free from 
rust, scale and oily spots and in a condition accept- 
able to the roofing contractor. 

Application of MAFTEX 

The deck should be well mopped with hot asphalt 
using not less than 25 lbs. per 100 sq. ft. of area 
and the MAFTEX Roof Insulating Board imbedded 




MAFTEX on Metal Roof Deck 



thoroughly by pressing the entire surface to the deck. 
A space of Yg' should be kept between all edges 
and the edges well coated. 

If more than one layer of MAFTEX is to be used 
mop uniformly and completely the top surface of 
each layer. The joints should be staggered and the 
boards imbedded in the hot asphalt. 

MAFTEX should be neatly cut to fit around pro- 
jections such as vent pipes, flag poles, etc., and at 
penthouses, walls, skylights, etc. 

Do not lay more MAFTEX than can be covered 
with roof covering in one day. Protect exposed 
edges of MAFTEX, when work is stopped, by a 
sheet of roofing paper weighted to hold it in place. 

Any "standard" built-up roofing may be applied to 
the MAFTEX. 

Architects' Short Form Specification 

(For Inclusion in Roofing Contractors* Work) 

The contractor for roofing shall furnish and apply 

layers of MAFTEX Roof Insulating Board to 

the metal roof deck before installing roofing. MAF- 
TEX shall be applied in accordance with the direc- 
tions of the maker published on Page 58 of the MAF- 
TEX Manual, dated 1928, and on file in the office 
of the architect. 



[58] 



MAFTEX Roof Insulating Board 

as a Base for Linoleum 
(Directions for Application) 



On Concrete 

The surface of the concrete floor should be 
brought to a uniformly smooth finish. Allowance 
should be made for the thickness of the MAFTEX 
in finishing the concrete floor. All floor surfaces 
should be coated with a water-proof primer. 

The concrete floor surface should next be covered 
with hot asphaltic cement or other approved water- 
proof cement and the MAFTEX completely im- 
bedded therein with the smooth surface uppermost. 
Carefully press down all boards and weight with 
sand bags along the edges to assure adhesion. Some- 
times a roller is used for this purpose. The upper 
surface of the MAFTEX must be kept clean of 
asphaltic cement. Do not force adjoining edges of 
the board into contact. 

The linoleum should be laid in an approved brand 
of linoleum cement over the MAFTEX base in 



accordance with the directions of the manufacturer 
of the linoleum. 

On Wood Floors 

The wood sub-floor should be of matched and 
dressed tongued and grooved stock. The ends of 
flooring should be so cut that all joints occur over 
floor joist. 

Over the wood floor lay MAFTEX Roof Insulat- 
ing Board. Each board should be nailed with 
4-penny shingle nails through the center and along 
all edges. Do not force adjoining edges of the 
Board into contact. MAFTEX shall be kept l/^^' 
away from all walls. 

The linoleum shall be laid in approved brand of 
linoleum cement over the MAFTEX base in accord- 
ance with the directions of the manufacturer of the 
linoleum. 





MAFTEX on Concrete Under Linoleum 



MAFTEX on Wood Under Linoleum 



[59] 



Related Data on Flat Roof Construction 



The satisfactory results possible with any flat roof 
are dependent upon several factors, some of which 
are described in the succeeding paragraphs. Each of 
these should be given due consideration in detailing 
and specifying and the work of installation should 
be regularly and carefully inspected. The attention 
of the architect or engineer is called to the fact that 
for some roofs it may be necessary to include under 
the specifications for the work of related trades, 
items either a part of or having a bearing on the roof 
deck construction, flashings, drains, etc. Often much 
time will be saved and trouble avoided by carefully 
checking on this point. 

Flashings 

The material for flashings should be carefully 
selected and specified. The neglect of these often 
forms one of the weakest points of the roof. It is 
usually poor economy to use any but the most per- 
manent materials and the best workmanship. This 
is particularly true when insulation is installed. 
Copper, lead, zinc, galvanized iron or tin are the 
usual flashing materials. 



STONt CONCKtTt OR. 
TCRR.A COTTA COPING 



5T0Nt _ 
FACING " 



^^^ 



m^m^. 



W MM- 



^^^ 



^^ 



5ECTI0N SHOWING 

FLA5HING FOR. A BKICK. 

PARAPET WALL 

FACED WITH 5T0NE 



COPPER. CAP FLMHIHG TO CXTtNO 
THR.OUCH 5R.ICK.W0R.IC fcND LAP 
5T0Nt ONt INCH 



COPPtR. bAiL FLASrtlHQ TUItNLO 
UP 7 mCHEi ON VMLL AND OUT 
ft INCHES OM R.OOF 




Flashings should be used at all intersections of 
vertical or projecting surfaces through the roof or 
against which the roof abuts such as walls, skylights, 
chimneys, etc. 

If the cap flashing is not to be built into the 
masonry the specification writer should make pro- 



COPPER. FLASHING 
3LLEVE 




Flashing for a Brick Parapet Wall Faced with Stone 
(Adopted from the Standards of the Copper and Brass Research Association) 



Flashing for Iron Vent with Copper Cap 

(Adopted from the Standards of the Copper and Brass Research Association) 



vision for the installation of flashing blocks. In any 
case, the mason and carpenter specification should 
include such provisions as may be necessary for 
related work. 

In connection with the use of copper flashings over 
concrete, it is important that the surface be made as 
smooth as possible either by a wash of neat cement 
or by elastic cement. Flashing materials should 
never come in contact with cinder concrete but the 
concrete should be painted with a heavy coating of 
asphalt paint before the copper is applied. 

On skylight or monitor curbs a flashing should be 
installed under the sill to take care of condensation 
which may form on the glass. 

When vent pipes or flag poles pass through the 
roof covering, they should be flashed and counter 
flashed. 

The Copper & Brass Research Association has, 
among others, made extensive studies of the prob- 
lem of flashings and valuable data is presented in 
the Association's Handbook '^Copper Flashings,'* 



[60] 



which may be obtained by writing to the Association 
at 25 Broadway, New York City. 

Roof Drains 

Care should be exercised in selecting the roof 
drains to see that they are of such form and size 
as will carry oflf the water without delay or danger of 
**backing up/' Such drains usually are furnished 
with flanges which provide all flashing necessary, 
but this is a point which should be investigated. 

When flat roofs are enclosed by parapet walls and 
have inside drainage systems, it is most important 
that adequate scuppers be provided to carry oflF 
water in case of clogging of the drains. If this 
point is neglected and water collects not only may 
it leak into the building by overtopping the flashing 



FLAMGt (A) TO E.XTtND OUT 
ON R.O0f A OlATANCE. EQUAL 
TO THE DIAMETER. OF TH^ 
COPPtR. TUbt (B) 



OASKtT STRAtNtR. 



COMPOilTION 
R.OOF 



CR.IMP GR.A.VE.L 
STOP 5OL0E.RtD OK 



MAFTLX-1 




Flashing for a Roof Drain from a Flat Roof 
(Adopted from the Standards of the Copper and Brass Research Association) 



but the weight may be sufficient to cause danger to 
the roof. The scupper should be amply large (at 
least 4'' X W) and should not have screens or any 
other obstruction. Balconies, roof decks or other 
areas enclosed by wall or balustrade should be pro- 
vided with scuppers. 

Nailing and Cant Strips 

Although not called for in the specifications it is 
sometimes advisable on roofs of large area to imbed 
a nailing block in a roof deck of concrete along all 
wall lines. The MAFTEX may then be nailed to 
this block. If this is to be done provisions for some 
should be made in the specifications for Concrete 
Work. 

Cant strips, when provided, should be set on top 
of the MAFTEX. This applies wherever cant strips 
are installed. 

Roofing 

It will be noted that the specifications and direc- 
tions call for the installation of MAFTEX Roof In- 
sulating Board by the roofing contractor. This pro- 
cedure is usually more satisfactory to all concerned 
as the contractor is then familiar with the condition 
of the base under the insulation and his responsibility 
is not divided with another contractor. The roofing 
contractor should not place insulation on any deck 
which is not in suitable condition to receive it. 



Instructions for Use of Roof Condensation Chart 



(See Page 63) 



Required Data 

To determine the number of layers of MAFTEX 
Roof Insulating Board required to prevent condensa- 
tion the following data are required. 

1 — Inside air temperature near roof line. 

2 — Relative humidity near ceiling line. 

3 — Extreme difference in temperature betw^een in- 
side and outside air. 

4 — Transmission coefficient of the uninsulated 
roof. 

With an exact knowledge of these four variables 
it is possible to calculate accurately the required 



insulation. Each is important, and the success or 
failure of the job will depend chiefly upon the 
accuracy with which they are determined. 

When insulation is to be applied to existing roofs, 
the temperature and humidity data should be taken 
from actual observations made near the ceiling line. 
Readings should be taken at a number of points, and 
under atmospheric conditions favoring condensation. 

In the case of a new building, assumptions must 
be made based on the use to which the building is to 
be put, and the design of the heating system. For 
external temperatures, statistics of the United States 
Weather Bureau may be used. 



[61] 



Procedure for Use of Condensation Chart 



Example 



1 — Using the upper section of the chart, locate the 
room temperature on the left hand scale. Pro- 
ject this value horizontally to the diagonal line 
indicating the relative humidity. 

2 — From the intersection found above pass down- 
ward to the horizontal line indicating the 
difference in temperature between the inside 
and outside air (as read on the left hand scale 
of the lower part of the diagram) . 

3 — Connect the intersection last found by means 
of a straight line with the reference point *'A/* 
and extend this line until it intersects the 
scale marked '^Required Transmission Coeffi- 
cient of the Insulated Roof." This gives the 
required coefficient of the roof. 

4 — From the accompanying table at the foot of 
this page select the transmission coefficient of 
the uninsulated roof and locate the value on 
the right hand scale of the diagram. 

5 — Projecting the value of the required coefficient 
vertically, and the coefficient of the uninsulated 
roof horizontally gives a final intersection 
point. If this point falls between the curves 
indicating one and two layers of MAFTEX, 
two layers should be used; if between two and 
three layers, three layers should be used. If 
more than five layers are indicated it is recom- 
mended that a ventilating engineer be con- 
sulted. 



HEAT TRANSMISSION 

of Various Types of Uninsulated Roof Decks 
(Expressed in B.t.u. per sq. ft. per degree F., per hour) 

TYPE OP ROOF Coefficient 

Steel Deck 0.84 

2* Stone Concrete 0.70 

gff " «' 0.65 

4» •< " 0.60 

Qtf « «' . , , , 0.52 

gff " <« ..,,[... 0.47 

2" Cinder Concrete 0.49 

4^ .« '« 0.35 

6" *' *' 0.27 

gff *« ** 0.22 

2" Stone Concrete with Cinder Pill 0.50 

g/f ** «« •* <' " 0.47 

4/r " <• *• " •' 0.44 

gff <« <* " " '* 0.40 

gn ti «' " " " 0.37 

2" Concrete 2" Hollow Tile 0.42 

2" " 4" " *' 0.33 

2» " 6" " ** 0.27 

2" " 8" " " 0.23 

4* " 2" " " 0.38 

4" *' 4" '* •' 0.30 

4" " 6" " " 0.25 

4» " 8" " " 0.22 

1" Wood Plank {7&") 0.49 

IW " " aV^n 0-39 

2" '* " (!%") 0.35 

2W " " (214") 0.28 

3" " " (2%") 0.26 



It is required to determine the number of layers 
of MAFTEX Roof Insulating Board to prevent con- 
densation on the underside of a 2'' concrete roof 
deck. Temperature and humidity conditions are 
as follows: 

Inside tempertaure near ceiling line — 66°, 

Relative humidity near ceiling line — 60%. 

Temperature of outside air — 12° below zero. 

This gives a difference in temperature between 
the inside and outside of 78^. 

Reference to the table shows that a 2'' stone 
concrete deck has a coefficient of 0.70 B.t.u. 

A graphic solution of the problem is indicated by 
the broken black lines on the diagram. The order 
of procedure is as follows: 

1 — Locate the inside temperature (66"^) on the 
upper left hand scale, and extend this hori- 
zontally to the diagonal line indicating 60% 
humidity. 

2 — Locate the temperature difference (78°) on 
the lower left-hand scale. Project this value 
horizontally to the right until it intersects the 
vertical line carried down from the intersection 
found in the upper part of the diagram. 

3 — Connect the intersection last found with point 
'*A" by means of a straight line. This line 
continued to its point of intersection with the 
scale marked * 'Required Transmission Coeffi- 
cient of the Insulated Roof" gives a value of 
0.25 B.t.u. 

4 — ^Locate the coefficient of the uninsulated roof 
(0.70 B.t.u.) on the right-hand scale. 

5 — Projecting vertically from the coefficient of the 
insulated roof (0.25 B.t.u.) and horizontally 
to the left from coefficient of the uninsulated 
roof (0.70 B.t.u.) gives an intersection be- 
tween one and two layers of MAFTEX. Two 
layers should be used. 



[62] 




CONDENSATION CHART 
See page 62 



[63] 




Airplane View of MacAndrews & Forbes Plant in Camden, N. J. 

For any additional or special information about MAFTEX or MAF-LATH 

applications write to 

MacAndrews & Forbes Company 

Business Established in U. 5. /4., 1870 
200 FIFTH AVENUE, NEW YORK 



[64] 




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